Isuzu Oasis S 1996 - 1996 ENGINE PERFORMANCE Self-Diagnostics - Oasis - 2.2L

Isuzu Oasis S 1996 - INTRODUCTION

If no faults were found while performing BASIC TESTING article, proceed with self-diagnostics. If no Diagnostic Trouble Codes (DTCs) or only pass codes are present after entering self-diagnostics, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

Isuzu Oasis S 1996 - SELF-DIAGNOSTIC SYSTEM HARD FAILURES

Hard failures cause Malfunction Indicator Light (MIL) to illuminate and remain on until problem is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined by retrieving DTCs and using DIAGNOSTIC TROUBLE CODES. See RETRIEVING CODES . If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, the vehicle runs but driveability will not be optimum.

Isuzu Oasis S 1996 - INTERMITTENT FAILURES

Intermittent failures may cause Malfunction Indicator light (MIL) to flicker or illuminate and go out after the intermittent fault goes away. The corresponding DTC will be retained in Powertrain Control Module (PCM) memory. If related fault does not reoccur within 50 starter operations, related DTC will be erased from PCM memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.

Isuzu Oasis S 1996 - MALFUNCTION INDICATOR LIGHT (MIL)

All models are equipped with an MIL. As a bulb check, light illuminates for 2 seconds when ignition is on and engine is not running. MIL also illuminates when a system failure has been detected and a corresponding DTC has been set in Powertrain Control Module (PCM) memory. Not all trouble codes will activate MIL. If MIL is on and no DTCs are in memory, problem may be intermittent. See INTERMITTENTS in TESTS W/O CODES article.

Isuzu Oasis S 1996 - RETRIEVING CODES

Turn ignition off. Connect PGM Tester or OBD-II scan tool to 16-pin Data Link Connector (DLC). DLC is located behind passenger side of center console.

Turn ignition on. If using PGM Tester, follow tester prompts. Diagnostic trouble code tests are not needed. If using scan tool, check for and note any DTCs. Also check for and note Freeze Frame Data. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table and proceed to appropriate DTC testing.

CAUTION:

DO NOT attempt any connection to 3-pin Data Link Connector (DLC) located near 2-pin service check connector.

Codes can also be accessed by using MIL. Connect SCS Service Connector (07PAZ-0010100) to 2-pin service check connector. Service check connector is located under passenger side of instrument panel near center console.

Turn ignition on. Diagnostic Trouble Codes (DTCs) will be indicated by a series of long and short flashes on MIL. The number of long flashes indicates the number in the 10s column. The number of short flashes indicates the number in the 1s column. For example, 4 long flashes followed by 3 short flashes would indicate DTC 43. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table and proceed to appropriate DTC testing.

Fig. 1: Isuzu Oasis S 1996 - Component Locations - Locating 2-Pin Service Check Connector (Oasis)

Isuzu Oasis S 1996 - DIAGNOSTIC TROUBLE CODE IDENTIFICATION

NOTE:

Not all codes apply to all models.

Isuzu Oasis S 1996 DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION

DTC	MIL Code	System Affected
P0106	3	Manifold Absolute Pressure (MAP) Sensor Low Input
P0107	3	Manifold Absolute Pressure (MAP) Sensor Low Input
P0108	3	Manifold Absolute Pressure (MAP) Sensor High Input
P0112	10	Intake Air Temperature (IAT) Sensor Low Input
P0113	10	Intake Air Temperature (IAT) Sensor High Input
P0116	86	Engine Coolant Temperature (ECT) Sensor Range/Performance
P0117	.....	Engine Coolant Temperature (ECT) Sensor Range/Performance
P0118	.....	Engine Coolant Temperature (ECT) Sensor Range/Performance
P0122	.....	Engine Coolant Temperature (ECT) Sensor Range/Performance
P0123	.....	Engine Coolant Temperature (ECT) Sensor Range/Performance
P0131 (1)	.....	Front Heated Oxygen Sensor (HO2S) Circuit Low Voltage (Sensor 1)
P0132 (1)	.....	Front Heated Oxygen Sensor (HO2S) Circuit High Voltage (Sensor 1)
P0133	.....	Rear Heated Oxygen Sensor (HO2S) Circuit Low Voltage (Sensor 2)
P0135	.....	Rear Heated Oxygen Sensor (HO2S) Circuit Low Voltage (Sensor 2)
P0137	63	Rear Heated Oxygen Sensor (HO2S) Circuit Low Voltage (Sensor 2)
P0138	63	Rear Heated Oxygen Sensor (HO2S) Circuit High Voltage (Sensor 2)
P0139	63	Rear Heated Oxygen Sensor (HO2S) Slow Response (Sensor 2)
P0141	65	Rear Heated Oxygen Sensor (HO2S) Heater Circuit Malfunction (Sensor 2)
P0171	45	System Too Lean
P0172	45	System Too Rich
P0301	71	Misfire Cylinder No. 1 Detected
P0301	71	Multiple Cylinder Misfire Detected
P0302	72	Misfire Cylinder No. 2 Detected
P0302	72	Multiple Cylinder Misfire Detected
P0303	73	Misfire Cylinder No. 3 Detected
P0303	73	Multiple Cylinder Misfire Detected
P0304	74	Misfire Cylinder No. 4 Detected
P0304	74	Multiple Cylinder Misfire Detected
P0305	75	Misfire Cylinder No. 5 Detected
P0305	75	Multiple Cylinder Misfire Detected
P0306	76	Misfire Cylinder No. 6 Detected
P0306	76	Multiple Cylinder Misfire Detected
P0325	23	Knock Sensor (KS) Circuit Malfunction
P0335	.....	Knock Sensor (KS) Circuit Malfunction
P0336	.....	Knock Sensor (KS) Circuit Malfunction
P0401	80	Exhaust Gas Recirculation (EGR) Insufficient Flow Detected
P0420	67	Catalyst System Efficiency Below Threshold
P0441	92	Evaporative Emission Control System Incorrect Purge Flow
P0452	91	Fuel Tank Pressure (FTP) Sensor Circuit Low Input
P0453	91	Fuel Tank Pressure (FTP) Sensor Circuit High Input
P0500	17	Vehicle Speed Sensor (VSS) Circuit Low Input
P0501	17	Vehicle Speed Sensor (VSS) Circuit Range/Performance
P0505	14	Idle Control System Malfunction
P0700(2)	70	Automatic Transaxle
P0715(2)	70	Automatic Transaxle
P0720(2)	70	Automatic Transaxle
P0725(2)	70	Automatic Transaxle
P0730(2)	70	Automatic Transaxle
P0740(2)	70	Automatic Transaxle
P0753(2)	70	Automatic Transaxle
P0758(2)	70	Automatic Transaxle
P1107	13	Barometric Pressure (BARO) Circuit Low Input
P1108	13	Barometric Pressure (BARO) Circuit High Input
P1253	21	VTEC System Malfunction
P1297	20	Electrical Load Detector Circuit Low Input
P1298	20	Electrical Load Detector Circuit High Input
P1300	.....	Multiple Cylinder Misfire Detected
P1336	54	Crankshaft Speed Fluctuation (CKF) Sensor Intermittent Interruption
P1337	54	Crankshaft Speed Fluctuation (CKF) Sensor No Signal
P1359	.....	Crankshaft Speed Fluctuation (CKF) Sensor No Signal
P1361	.....	Crankshaft Speed Fluctuation (CKF) Sensor No Signal
P1362	.....	Crankshaft Speed Fluctuation (CKF) Sensor No Signal
P1381	9	Cylinder Position (CYP) Sensor Intermittent Interruption
P1382	9	Cylinder Position (CYP) Sensor No Signal
P1456	90	Evaporative Emission Control System Leak Detected (Fuel Tank System)
P1457	90	Evaporative Emission Control System Leak Detected (EVAP Canister System)
P1459	92	Evaporative Emission Purge Flow Switch Malfunction
P1491	12	EGR Valve Lift Insufficient Detected
P1498	12	EGR Valve Lift High Voltage
P1508	14	Idle Air Control Valve Circuit Failure
P1509	14	Idle Air Control Valve Circuit Failure
P1607	(-)	Powertrain Control Module (PCM) Internal Circuit Failure A
P1660(2)	70	A/T FI Data Line Failure
P1681(2)	30	A/T FI Signal A Low Input
P1682(2)	30	A/T FI Signal A High Input
P1686(2)	31	A/T FI Signal B Low Input
P1687(2)	31	A/T FI Signal B High Input
P1705(2)	70	Automatic Transaxle
P1706(2)	70	Automatic Transaxle
P1753(2)	70	Automatic Transaxle
P1758(2)	70	Automatic Transaxle
P1768(2)	70	Automatic Transaxle
P1785(2)	70	Automatic Transaxle
P1786(2)	70	Automatic Transaxle
P1790(2)	70	Automatic Transaxle
P1791(2)	70	Automatic Transaxle
P1792(2)	70	Automatic Transaxle
P1793(2)	70	Automatic Transaxle
P1794(2)	70	Automatic Transaxle
P1870(2)	70	Automatic Transaxle
P1873(2)	70	Automatic Transaxle
P1879(2)	70	Automatic Transaxle
P1885(2)	70	Automatic Transaxle
P1886(2)	70	Automatic Transaxle
P1888(2)	70	Automatic Transaxle
P1890(2)	70	Automatic Transaxle
P1891(2)	70	Automatic Transaxle
(1) If codes appear other than those listed in table, verify code. If code is not listed, replace PCM. (2) See appropriate ELECTRONIC CONTROLS article in AUTOMATIC TRANSMISSIONS section.

Isuzu Oasis S 1996 - FREEZE FRAME DATA

Freeze frame data indicates engine operating conditions when the first malfunction, misfire or fuel trim malfunction was detected.

Isuzu Oasis S 1996 - PCM RESET PROCEDURE/CLEARING CODES

NOTE:

Some models have an anti-theft code built into the radio circuit. Clearing codes cancels clock and radio settings; make note of settings before beginning reset procedure. After PCM reset, the radio will not function until code is entered.

To reset Powertrain Control Module (PCM) (clear codes), use PGM-FI tester or scan tool following manufacturer's instructions. Codes can also be cleared by turning ignition off. Remove BACK UP (7.5-amp) fuse from underhood fuse/relay block. Leave fuse out for 10 seconds to reset PCM. Disconnect PGM-FI tester or scan tool from DLC.

Isuzu Oasis S 1996 - PCM LOCATION

ECM is located to right of Transmission Control Module (TCM).

Isuzu Oasis S 1996 - TEST EQUIPMENT

All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated differently in testing procedure.

Use Backprobe Set (07SAZ-001000A) (2 required) to backprobe Powertrain Control Module (PCM) when directed by testing. See Fig. 2 . For PCM connector terminal identification, see CONNECTOR IDENTIFICATION. DO NOT puncture wire insulation. Place tester probe into contact with terminal, from terminal side of wiring harness connectors in engine compartment. For female connectors, just touch terminal lightly with tester probe. DO NOT insert probe into terminal.

Fig. 2: Isuzu Oasis S 1996 - Component Locations - Using Backprobe Set (Oasis)

Isuzu Oasis S 1996 - CONNECTOR IDENTIFICATION

Fig. 3: Isuzu Oasis S 1996 - Component Locations - Identifying Data Link Connector (DLC) Connector Terminals (Oasis)

Fig. 4: Isuzu Oasis S 1996 - Component Locations - PCM Harness Connector Terminal ID (Oasis)

Isuzu Oasis S 1996 - CIRCUIT TESTS

NOTE:

When there is no DTC stored, MIL will stay on if the SCS service connector is connected and ignition switch is on.

When directed by testing procedure to install test equipment, see TEST EQUIPMENT .

Isuzu Oasis S 1996 - NO DTC - POWERTRAIN CONTROL MODULE (PCM)

NOTE:

If symptom is intermittent, check for loose fuse No. 1 BACK UP LIGHTS (10-amp). Fuse is located in underdash fuse/relay box. Also check for poor connection at PCM terminal A18 or an intermittent open in wire between PCM terminal A18 and gauge assembly.

1. If Malfunction Indicator Light (MIL) never comes on, even for 2 seconds after ignition is turned on, go to next step. If MIL stays on or comes on after 2 seconds, go to step 5).
2. Turn ignition on. If low oil pressure light is on, go to next step. If low oil pressure light is not on, replace fuse No. 1 BACK UP LIGHTS (10-amp) and/or repair short in wire between fuse and gauge assembly. See WIRING DIAGRAMS section.
3. If oil pressure light is on, try to start engine. If engine starts, go to next step. If engine does not start, turn ignition on. Measure voltage between ground and PCM terminals A10 (Black wire) and A23 (Black wire) individually. See Fig. 4 . If less than one volt exists, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM. If one volt or more exists, repair open in Black wire(s) between PCM and ground (G101), located at left side of intake manifold.
4. Turn ignition off. Using jumper wire, connect PCM terminal A18 to ground. See Fig. 4 . Turn ignition on. If MIL illuminates, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM. If MIL does not illuminate, replace MIL bulb and/or repair open in wire between PCM connector terminal A18 and gauge assembly. See WIRING DIAGRAMS section.
5. Connect scan tool or Honda PGM tester to DLC connector. Turn ignition on. Read DTCs (if present). See RETRIEVING CODES . If DTCs are present, go to DIAGNOSTIC TROUBLE CODE IDENTIFICATION . After identifying DTC, go to appropriate Diagnostic Trouble Code (DTC) test. If DTCs are not present, go to next step.
6. Turn ignition off. Connect SCS service connector to service check connector. See RETRIEVING CODES . Turn ignition on. If DTCs are not present using MIL, go to next step. If DTCs are present using MIL, repair open or short in Light Green wire between PCM terminal C8 and DLC. See Fig. 4 . See WIRING DIAGRAMS section. Go to DIAGNOSTIC TROUBLE CODE IDENTIFICATION . After identifying DTC, go to appropriate Diagnostic Trouble Code (DTC) test.
7. Attempt to start engine. If engine starts, go to next step. If engine does not start, go to step 10).
8. Turn ignition off. Turn ignition on. Measure voltage between PCM terminal terminals C7 (Red wire) and D11 (Green/Blue wire). If approximately 5 volts exists, go to next step. If approximately 5 volts does not exist, repair short to ground in wire between PCM connector terminal C7 and service check connector. See WIRING DIAGRAMS section.
9. Turn ignition off. Disconnect PCM connector "A". See Fig. 4 . Turn ignition on. If MIL is on, repair short to ground in wire between PCM terminal A18 and MIL. See WIRING DIAGRAMS section. If MIL is not on, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
10. Inspect ECM/PCM fuse (10-amp). Fuses are located in underhood fuse/relay box. If fuse is okay, go to next step. If fuse is open, repair short in wire between fuse and PGM-FI main relay. See WIRING DIAGRAMS section. Replace fuse.
11. Inspect fuse No. 2 FUEL PUMP (15-amp). If fuse is okay, go to next step. If fuse is open, repair short in wire between underdash fuse/relay box and PGM-FI main relay. See WIRING DIAGRAMS section. Replace fuse.
12. Turn ignition on. While observing MIL, disconnect 3-pin Manifold Absolute Pressure (MAP) sensor, Throttle Position (TP) sensor, EGR valve lift sensor and Fuel Tank Pressure (FTP) sensor (if equipped), each one at a time. If MIL goes off for a few seconds and then comes back on, go to next step. If MIL does not go off for a few seconds and then come back on, replace sensor that caused MIL to go out.
13. Turn ignition off. Disconnect PCM connector "D". See Fig. 4 . Check for continuity between ground and PCM connector terminals D4 and D10 individually. If continuity does not exist, go to next step. If continuity exists, repair short to ground in wire between PCM connector terminal D4 and MAP sensor, or wire between PCM connector terminal D10 and TP sensor, EGR valve lift sensor or FTP sensor (if equipped).
14. Disconnect injector resistor, EVAP purge control solenoid valve, front (primary) HO2S (sensor 1) and IAC valve connectors. Turn ignition on. Measure voltage between ground and PCM connector terminals A11 and A24 individually. See Fig. 4 . If battery voltage exists, go to next step. If battery voltage does not exist, check for poor connection at PGM-FI main relay or repair open in wire between PCM connector terminals A11 and A24 and PGM-FI main relay. See WIRING DIAGRAMS section.
15. If battery voltage was present, reconnect all sensor connectors. Reconnect PCM connector. Turn ignition on. Measure voltage between ground and PCM connector terminals A9 and A22 individually. If voltage reading for either terminal is less than one volt, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM. If voltage reading for either terminal is more than one volt, repair open in wire between ground (G101) located left side of intake manifold and PCM terminal(s) terminals A9 and/or A22. See WIRING DIAGRAMS section.

Isuzu Oasis S 1996 - DTC P0106 - MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine and run it at 1000 RPM for one minute with transmission in Park or Neutral. If DTC P0106 is indicated, go to step 3). If DTC P0106 is not indicated, turn ignition off. Turn ignition on. Check MAP sensor using scan tool or PGM tester. If atmospheric pressure is not indicated, replace MAP sensor. If atmospheric pressure is indicated, start engine.
2. Raise and hold engine speed to 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Turn ignition off. Restart engine. Check MAP sensor using scan tool or PGM tester. If MAP sensor reading is 12.0 in. Hg or less one second after starting, MAP sensor is okay at this time. If MAP sensor reading is not as specified one second after starting, replace MAP sensor.
3. If DTC P0106 is indicated, check for blocked vacuum port, or restricted or leaking vacuum hose between throttle body and MAP sensor. Repair blockage or leak as necessary. If there is no blockage or leaks, turn ignition off. Turn ignition on. Check MAP sensor using scan tool. If atmospheric pressure is not indicated, replace MAP sensor. If atmospheric pressure is indicated, start engine.
4. Raise and hold engine speed to 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Turn ignition off. Restart engine. Check MAP sensor using scan tool. If MAP sensor reading is 12.0 in. Hg or less within one second after starting, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM. If MAP sensor reading is not 12.0 in. Hg or less one second after starting, replace MAP sensor.

Isuzu Oasis S 1996 - DTC P0107 - MAP SENSOR

1. Turn ignition on. Check MAP sensor using scan tool. If approximately zero in. Hg is not indicated, problem is intermittent. Check for poor connections or loose wires at 14-pin connector (on right shock tower), MAP sensor connector, and PCM connector. If approximately zero in. Hg is indicated, turn ignition off and disconnect MAP sensor connector.
2. Turn ignition on. Check MAP sensor using scan tool. If approximately zero in. Hg is not indicated, replace MAP sensor. If approximately zero in. Hg is indicated, measure voltage between MAP sensor connector terminals No. 1 (VCC1) and 2 (SG1). See Fig. 7 . If approximately 5 volts exists, go to step 4). If approximately 5 volts does not exist, repair open in VCC1 circuit between PCM connector terminal D4 and MAP sensor connector terminal No. 1. See WIRING DIAGRAMS section.
3. Turn ignition off. Disconnect PCM connector "D". See Fig. 4 . Measure resistance between MAP sensor connector terminal No. 3 and ground. See Fig. 7 . If continuity exists, repair short in MAP circuit between PCM connector terminal D3 and MAP sensor connector No. 3. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0108 - MAP SENSOR

1. Start engine. Raise and hold engine speed to 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Let engine idle. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, failure is intermittent. System is okay at this time. Check for poor connections or loose wires at 14-pin connector (on right shock tower), MAP sensor connector, and PCM connector.
2. If MAP sensor reading is 30.0 in. Hg or more, turn ignition off. Disconnect MAP sensor connector. Install jumper wire between MAP sensor harness connector terminals No. 2 and No. 3. See Fig. 7 . Turn ignition on. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, replace MAP sensor. If MAP sensor reading is 30.0 in. Hg or more, turn ignition off.
3. Remove jumper wire from MAP sensor connector. Turn ignition on. Measure voltage between MAP sensor connector terminals No. 1 (VCC1) and 2 (SG1). See Fig. 7 . If approximately 5 volts exists, turn ignition off and go to next step. If approximately 5 volts does not exist, repair open in SG1 circuit between PCM connector D12 and MAP sensor connector terminal No. 2. See WIRING DIAGRAMS section.
4. Install jumper wire between PCM connector terminals D3 (MAP) and D12 (SG1). See Fig. 4 . Turn ignition on. Check MAP sensor using scan tool. If MAP sensor reading is not 30.0 in. Hg or more, repair open in MAP circuit between MAP sensor and PCM connector terminal D3. If MAP sensor reading is 30.0 in. Hg or more, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0112 - INTAKE AIR TEMPERATURE (IAT) SENSOR

1. Turn ignition on. Check IAT sensor using scan tool. If 302?F (150?C) or more is displayed, go to next step. If 302?F (150?C) or more is not displayed, check if correct ambient temperature is displayed. If correct ambient temperature is not displayed, replace IAT sensor. If engine is warm, displayed temperature will be higher than ambient temperature. If correct ambient temperature is displayed, failure is intermittent. Check for poor connections or loose wires at IAT sensor connector and PCM connector. See WIRING DIAGRAMS section.
2. Disconnect IAT sensor. Check IAT sensor using scan tool. If 302?F (150?C) or more is not displayed, replace IAT sensor. If 302?F (150?C) or more is displayed, turn ignition off. Disconnect PCM connector "D". See Fig. 4 . Check for continuity between IAT sensor connector terminal No. 2 (Red/Yellow wire) and ground. If continuity exists, repair short in wiring between IAT sensor and PCM terminal D8 (Red/Yellow wire). See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0113 - INTAKE AIR TEMPERATURE (IAT) SENSOR

1. Turn ignition on. Check IAT sensor using scan tool. If less than -4?F (-20?C) or less is not indicated, problem is intermittent. Check for poor connections or loose wires in IAT circuit between IAT sensor connector and PCM connector. See WIRING DIAGRAMS section.
2. If -4?F (-20?C) or less is indicated, disconnect IAT connector. Install jumper wire between IAT sensor connector terminals. Using scan tool, check intake air temperature. If -4?F (-20?C) or less is not indicated, replace IAT sensor.
3. If -4?F (-20?C) or less is indicated, turn ignition off. Connect jumper wire between PCM connector terminals D8 and D11. See Fig. 4 . Turn ignition on. Using scan tool, check intake air temperature. If -4?F (-20?C) or less is not indicated, repair open in wiring between IAT sensor and PCM connector terminals D8 and D11. See WIRING DIAGRAMS section. If -4?F (-20?C) or less is indicated, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0116 - ECT SENSOR

Start engine. Raise and hold engine speed to 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Let engine idle. Using scan tool, check ECT. If 176-194?F (80-90?C) is indicated, problem is intermittent. System is okay at this time. Check cooling system. If 176-194?F (80-90?C) is not indicated, check cooling system. If cooling system is okay, replace ECT sensor.

Isuzu Oasis S 1996 - DTC P0117 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Turn ignition on. Using scan tool, check ECT. If 302?F (150?C) or more is not indicated, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in ECT circuits between ECT sensor connector and PCM connector. See WIRING DIAGRAMS section.
2. If 302?F (150?C) or more is indicated, disconnect ECT sensor connector. Using scan tool, check ECT. If 302?F (150?C) or more is not indicated, replace ECT sensor. If 302?F (150?C) or more is indicated, turn ignition off. Disconnect PCM connector "D". See Fig. 4 .
3. Check for continuity between ECT connector Red/White wire and ground. If continuity exists, repair short in Red/White wire between ECT sensor and PCM connector terminal D2. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0118 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Turn ignition on. Using scan tool, check ECT. If -4?F (-20?C) or less is not indicated, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in ECT circuits between ECT sensor connector, and PCM connector. See WIRING DIAGRAMS section.
2. If -4?F (-20?C) or less is indicated, disconnect ECT sensor connector. Install jumper wire between ECT harness connector terminals. Using scan tool, check ECT. If -4?F (-20?C) or less is not indicated, replace ECT sensor. If -4?F (-20?C) or less is indicated, turn ignition off.
3. Install jumper wire between PCM connector terminals D2 and D11. Turn ignition on. Using scan tool, check ECT. If -4?F (-20?C) or less is not indicated, repair open in ECT and SG2 circuit between ECT sensor and PCM connector terminals D2 and D11. See WIRING DIAGRAMS section. If -4?F (-20?C) or less is indicated, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0122 - THROTTLE POSITION (TP) SENSOR

1. Turn ignition on. Using scan tool, check TP sensor. If reading is approximately 10% with throttle fully closed and 90% with throttle fully opened, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in TP circuits between TP sensor connector and PCM connector. See WIRING DIAGRAMS section.
2. If reading is not approximately 10% with throttle fully closed and 90% with throttle fully opened, turn ignition off. Disconnect TP sensor connector. Turn ignition on. Measure voltage between TP sensor harness connector terminals No. 1 (SG2) and 3 (VCC2). See Fig. 5 . If reading is approximately 5 volts, go to step 4).
3. If reading is not approximately 5 volts, measure voltage between PCM connector terminals D10 and D11. See Fig. 4 . If reading is approximately 5 volts, repair open in SG2 circuit between PCM connector TP sensor terminal. See WIRING DIAGRAMS section. If reading is not approximately 5 volts, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
4. Turn ignition off. Measure resistance between TP sensor terminals No. 1 (SG2) and No. 2 (TP) with throttle closed. See Fig. 5 . If resistance is not approximately 500 ohms, replace TP sensor. If resistance is approximately 500 ohms, measure resistance between TP sensor terminals No. 2 (TP) and 3 (VCC2) with throttle fully closed.
5. If resistance is not approximately 4500 ohms), replace TP sensor. If resistance is approximately 4500 ohms, reconnect TP sensor and go to next step.
6. Turn ignition on. Measure voltage between PCM connector terminals D1 and D11. See Fig. 4 . If voltage is approximately .5 volt with throttle fully closed and 4.5 volts with throttle fully open, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
7. If voltage is not approximately .5 volt with throttle fully closed and 4.5 volts with throttle fully open, repair short in circuit between PCM connector terminal D1 and TP sensor. See WIRING DIAGRAMS section.
8. Turn ignition off. Disconnect TCM connectors. Turn ignition on. Measure voltage between PCM connector terminals D1 and D11. If voltage is approximately .5 volt with throttle fully closed and 4.5 volts with throttle fully open, replace Transmission Control Module (TCM).
9. If voltage is not approximately .5 volt with throttle fully closed and 4.5 volts with throttle fully open, repair short in circuit between PCM connector terminal D1, TCM connector, and TP sensor connector. See WIRING DIAGRAMS section.

Fig. 5: Isuzu Oasis S 1996 - Component Locations - Identifying TP Sensor Harness Connector Terminals (Oasis)

Isuzu Oasis S 1996 - DTC P0123 - THROTTLE POSITION (TP) SENSOR

1. Turn ignition on. Using scan tool, check TP sensor. If reading is approximately 10% with throttle fully closed and 90% with throttle fully opened, problem is intermittent. System is okay at this time. Check for poor connections or loose wires in TP circuit between TP sensor connector, and PCM connector. See WIRING DIAGRAMS section.
2. If reading is not approximately 10% with throttle fully closed and 90% with throttle fully opened, turn ignition off. Disconnect TP sensor connector. Turn ignition on. Measure voltage between TP sensor wiring harness connector terminals No. 1 (SG2) and 3 (VCC2). See Fig. 5 . If reading is approximately 5 volts, replace throttle body.
3. If reading is not approximately 5 volts, measure voltage between PCM connector terminals D10 and D11. See Fig. 4 . If reading is approximately 5 volts, repair open in SG2 circuit between PCM connector and TP sensor. See WIRING DIAGRAMS section. If reading is not approximately 5 volts, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0131 - FRONT HO2S SENSOR 1

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Road test vehicle with transmission in "2" position (A/T) or 4th gear (M/T). Using scan tool, check HO2S (sensor 1) output voltage during acceleration to Wide Open Throttle (WOT).
2. If voltage does not stay at .1 volt or less, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 1) and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If voltage stays at .1 volt or less, check fuel pressure. See FUEL SYSTEM in BASIC TESTING article. If fuel pressure is not within specification, repair fuel supply system as necessary. If fuel pressure is within specification, turn ignition off.
3. Disconnect HO2S (sensor 1) connector. Start engine and run at idle. Using scan tool, check HO2S (sensor 1) output voltage. If output voltage does not stay at .1 volt or less, replace HO2S (sensor 1). If voltage stays at .1 volt or less, turn ignition off. Disconnect PCM connector "D". See Fig. 4 .
4. Measure resistance between ground and White/Red wire in HO2S harness connector. If continuity exists, repair short to ground in White/Red wire. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0132 - FRONT HO2S SENSOR 1

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Road test vehicle with transmission in "2" position (A/T) or 4th gear (M/T). Using scan tool, check HO2S (sensor 1) output voltage during deceleration using completely closed throttle.
2. If voltage does not stay at one volt or more, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 1) and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If voltage stays at one volt or more, turn ignition off.
3. Disconnect HO2S (sensor 1) connector. Install jumper wire between HO2S harness connector terminals No. 1 and 2. See Fig. 6 . Turn ignition on. Using scan tool, check HO2S (sensor 1) output voltage. If output voltage is not one volt or more, replace HO2S (sensor 1).
4. If output voltage is one volt or more, turn ignition off. Connect jumper wire between PCM connector terminals D7 and D11. Turn ignition on. Using scan tool, check HO2S output voltage.
5. If voltage is not one volt or more, repair open in HO2S (sensor 1) circuit between PCM harness connector and HO2S harness connector. See WIRING DIAGRAMS section. If voltage is one volt or more, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Fig. 6: Isuzu Oasis S 1996 - Component Locations - Heated Oxygen Sensor (HO2S) Harness Connector Terminal ID (Oasis)

Isuzu Oasis S 1996 - DTC P0133 - FRONT HO2S SENSOR 1

NOTE:

If DTCs P0131, P0132 and/or P0135 are also present, trouble shoot those DTCs before DTC P0133.

1. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Let engine idle. Connect SCS Service Connector (07PAZ-0010100) . Test drive vehicle at 55 MPH, with transmission in D4 position (A/T) or 5th gear (M/T), until readiness code comes on.
2. If DTC P0133 is not indicated, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 1) and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If DTC P0133 is indicated, replace front HO2S (sensor 1).

Isuzu Oasis S 1996 - DTCS P0135 & P0141 - HO2S HEATER

NOTE:

DTC P0135 is for front HO2S heater circuit and DTC P0141 is for rear HO2S heater circuit.

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. If DTC P0135 or P0141 is not indicated, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at appropriate HO2S sensor and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary.
2. If DTC P0135 or P0141 is indicated, turn ignition off. Disconnect appropriate HO2S connector. Measure resistance between terminals No. 3 and 4 of appropriate HO2S sensor. See Fig. 6 . If resistance is not 10-40 ohms, replace appropriate HO2S. If resistance is 10-40 ohms, check for continuity between ground and terminals No. 3 and 4 individually on appropriate HO2S.
3. If continuity exists, replace appropriate HO2S. If continuity does not exist, turn ignition on. Measure voltage between HO2S harness connector terminals No. 3 and 4. If battery voltage exists, go to step 8). If battery voltage does not exist, go to next step.
4. Measure voltage between HO2S harness connector terminal No. 3 and ground.
5. If battery voltage does not exist, repair open in power feed circuit to appropriate HO2S connector. See WIRING DIAGRAMS section. If battery voltage exists, turn ignition off. Reconnect HO2S connector. Disconnect PCM connector "A". See Fig. 4 . Turn ignition on.
6. Measure voltage between PCM connector terminal A6 (A5 for HO2S sensor 2) and terminal A10.
7. If voltage is .1 volt or less, repair open in circuit between PCM and appropriate HO2S. See WIRING DIAGRAMS section. If voltage is not .1 volt or less, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
8. Turn ignition off. Disconnect PCM connector "A". See Fig. 4 . Vheck for continuity between PCM connector terminal A6 (A5 for HO2S sensor 2) and ground.
9. If continuity exists, repair short in circuit between PCM and appropriate HO2S. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0137 - REAR HEATED OXYGEN SENSOR (HO2S) SENSOR 2

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Using scan tool, check HO2S (sensor 2) output voltage with engine speed at 3000 RPM.
2. If voltage does not stay at .3 volt or less, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 2) and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If voltage stays at .3 volt or less, turn ignition off.
3. Disconnect HO2S (sensor 2) connector. Start engine. Using scan tool, check HO2S (sensor 2) output voltage. If output voltage does not stay at .3 volt or less, replace HO2S (sensor 2).
4. If output voltage stays at .3 volt or less, turn ignition off. Disconnect PCM connector "D". See Fig. 4 . Check for continuity between ground and HO2S (sensor 2) harness connector terminal No. 1. If continuity exists, repair short in White/Red wire between PCM connector terminal D14 and HO2S harness connector. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Fig. 7: Isuzu Oasis S 1996 - Component Locations - HO2S Circuit (Oasis)

Isuzu Oasis S 1996 - DTC P0139 - REAR HEATED OXYGEN SENSOR (HO2S) SENSOR 2

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Using scan tool, check HO2S (sensor 2) output voltage with engine speed at 3000 RPM.
2. If voltage does not stay at .3-.6 volt for one minute, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 2) and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If voltage stays at .3-.6 volt for one minute, replace HO2S (sensor 2).

Isuzu Oasis S 1996 - DTCS P0171 & P0172 - FUEL SUPPLY SYSTEM

NOTE:

DTC P0171 indicates fuel system is too lean and DTC P0172 indicates fuel system is too rich.

1. If DTCs P0106, P0107, P0108, P0135, P0141, P0401, P0441, P1491, or P1498 are displayed, repair those DTCs first. Check fuel pressure. See FUEL SYSTEM in BASIC TESTING article. If fuel pressure is okay, go to next step. If fuel pressure is too high, check fuel pressure regulator and fuel return pipe. Repair as necessary. If fuel pressure is too low, check fuel pump, fuel feed pipe, fuel filter and fuel pressure regulator. Repair as necessary.
2. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Using scan tool, check HO2S (sensor 1) output voltage. If voltage does stays at less than .3 volt or more than .6 volt, replace HO2S (sensor 1). If voltage does not stay at less than .3 volt or more than .6 volt, go to next step.
3. Using vacuum pump, apply vacuum to EVAP purge control solenoid valve from intake manifold side. If vacuum does not hold, replace EVAP purge control solenoid valve. If vacuum holds, go to next step.
4. Turn ignition on. Using scan tool, check MAP sensor. If atmospheric pressure is not indicated, replace MAP sensor. If atmospheric pressure is indicated, start engine and go to next step.
5. Using scan tool, check MAP sensor. If MAP reading of 11.8 in. Hg vacuum or less is not indicated within one second after starting engine, replace MAP sensor. If MAP reading of 11.8 in. Hg vacuum or less is indicated within one second after starting engine, check valve clearance and EGR system (if equipped). If valve clearance and EGR system are okay, replace fuel injectors.

Isuzu Oasis S 1996 - DTCS P0301, P0302, P0303, P0304, P0305 & P0306 - MISFIRE IN ONE CYLINDER

NOTE:

If DTCs P0106, P0171, P0172, P0401, P0441, P1361, P1362, P1381, P1382, P1491, or P1498 are displayed, repair those DTCs first.

DTC

• DTC P0301 indicates cylinder No. 1 misfire.
• DTC P0302 indicates cylinder No. 2 misfire.
• DTC P0303 indicates cylinder No. 3 misfire.
• DTC P0304 indicates cylinder No. 4 misfire.
• DTC P0305 indicates cylinder No. 5 misfire.
• DTC P0306 indicates cylinder No. 6 misfire.

1. Start engine and listen for clicking sound at fuel injector in problem cylinder. If injector clicks, go to next step. If injector does not click, check for open or short in harness between fuel injector and PCM, and fuel injector and injector resistor. See WIRING DIAGRAMS section. Repair wiring as necessary. If wiring is okay, check fuel injector resistor, replace fuel injector, and substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
2. Check freeze data. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. If there is no freeze data of misfiring, clear DTCs. Exchange spark plug from misfiring cylinder with one from another cylinder. Connect SCS service connector. Test-drive vehicle several times in the range of freeze data. If there is no freeze data of misfiring, test drive vehicle under various conditions to try to duplicate malfunction. If DTC P0301, P0302, P0303, P0304, P0305, or P0306 is not indicated, misfire condition is intermittent. Plugs are firing properly at this time.
3. If misfiring occurs in other cylinder whose spark plug was exchanged, replace spark plugs. If misfiring does not occur in other cylinder whose spark plug was exchanged, exchange fuel injector with one from another cylinder. Let engine idle for 2 minutes. Test-drive vehicle several times in the range of freeze data. If there is no freeze data of misfiring, test drive vehicle under various conditions to try to duplicate malfunction.
4. If DTC P0301, P0302, P0303, P0304, P0305, or P0306 is not indicated, misfire condition is intermittent. Injectors are operating properly at this time. If misfiring occurs in other cylinder whose injector was exchanged, replace faulty fuel injector. If misfiring does not occur in other cylinder whose fuel injector was exchanged, check valve clearance, engine compression and Crankshaft Position (CKP) sensor (if equipped).

Isuzu Oasis S 1996 - DTCS P0301 OR P1300, P0302, P0303, P0304, P0305 & P0306 - MISFIRE OF MULTIPLE CYLINDERS

NOTE:

If DTCs P0106, P0171, P0172, P0401, P1491, P1498, P0505, P1361, P1362, P1381, P1382 and/or P1508 are also stored, diagnose those DTCs first.

1. If misfire condition occurs only at low RPM and load, check IAC valve, MAP sensor, EGR system, fuel pressure, CKP sensor, and valve clearance. If misfire condition occurs only while accelerating, check ignition system, fuel pressure, ICM, and MAP sensor.
2. If misfire condition occurs only at high RPM and load, check fuel pressure, ignition system, ICM, MAP sensor, valve clearance and CKP sensor. If misfire condition is not specific, check fuel pressure, ignition system, MAP sensor, ICM, CKP sensor, and valve clearance. If misfire condition does not reoccur, check fuel quality, lack of fuel, or carbon deposits.

Isuzu Oasis S 1996 - DTC P0325 - KNOCK SENSOR (KS)

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Let engine idle. Raise and hold engine speed at 3000-4000 RPM with transmission in Park or Neutral for at least 60 seconds.
2. If DTC P0325 is not indicated, system is functioning properly at this time. Failure is intermittent (test drive may be necessary). Check for poor connections or loose wires at KS and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If DTC P0325 is indicated, turn ignition off.
3. Disconnect KS connector. Check for continuity between ground and PCM connector terminal D6. See Fig. 4 . If continuity exists, repair short in Red/Blue wire between PCM and KS. See WIRING DIAGRAMS section. If continuity does not exist, check continuity of Red/Blue wire between PCM and KS.
4. If continuity does not exist, repair open in Red/Blue wire between PCM and KS. See WIRING DIAGRAMS section. If continuity exists, substitute a known good KS and recheck. If DTC P0325 is not indicated, replace original KS. If DTC P0325 is indicated, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTCS P0335, P0336, P1361 & P1362 - CRANKSHAFT POSITION/TOP DEAD CENTER (CKP/TDC) SENSOR

NOTE:

DTC P0335 indicates a malfunction in CKP sensor circuit. DTC P0336 indicates intermittent interruption in CKP sensor circuit. DTC P1361 indicates intermittent interruption in TDC sensor circuit. DTC P1362 indicates no signal in TDC sensor circuit.

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. If DTC P0335, P0336, P1361 and/or P1362 are indicated, go to next step. If DTC P0335, P0336, P1361 and/or P1362 are not indicated, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires CKP/TDC sensor connector, and PCM connector. See WIRING DIAGRAMS section. Repair as necessary.
2. Turn ignition off. Disconnect CKP/TDC sensor connector. Measure resistance between CKP/TDC sensor terminals. See CKP/TDC SENSOR RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, replace CKP/TDC sensor. See Fig. 8 .
   

   Isuzu Oasis S 1996 CKP/TDC SENSOR RESISTANCE
   

   Sensor	Terminals	Resistance (Ohms)
   CKP	3 & 4	500-1000
   TDC	1 & 2	500-1000

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   Fig. 8: Isuzu Oasis S 1996 - Component Locations - Identifying CKP/TDC Sensor Connector (Oasis)
   

3. Check for continuity between each CKP/TDC sensor terminals No. 1, 2, 3 and 4 and ground. See Fig. 8 . If continuity exists, replace CKP/TDC sensor. If continuity does not exist, reconnect CKP/TDC sensor. Disconnect PCM connector "C". See Fig. 4 . Measure resistance between PCM terminals. See CKP/TDC SENSOR CIRCUIT RESISTANCE table. If resistance is as specified, go to next step. If resistance is not as specified, repair open in appropriate circuit. See WIRING DIAGRAMS section. See Fig. 4 .
   

   Isuzu Oasis S 1996 CKP/TDC/CYP SENSOR CIRCUIT RESISTANCE
   

   Sensor	Terminals	Resistance (Ohms)
   CKP	C2 & C12	500-1000
   TDC	C3 & C13	500-1000

4. Check for continuity between ground and PCM terminals C2 and C3 individually. See Fig. 4 . If continuity exists, repair short in appropriate wire to PCM terminals C2 and/or C3. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P0401 - EXHAUST GAS RECIRCULATION (EGR) SYSTEM

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Connect SCS service connector. Test-drive vehicle and ensure there is no electrical load. Decelerate vehicle from 55 MPH for at least 5 seconds. If DTC P0401 is not indicated, system is okay at this time. Problem is intermittent. If DTC P0401 is indicated, clean intake manifold EGR port. Clean passage inside EGR valve or replace valve as necessary.

Isuzu Oasis S 1996 - DTC P0420 - THREE-WAY CATALYTIC CONVERTER (TWC)

NOTE:

If DTCs P0136, P0137, P0138, P0139 or P0141 are stored, repair those DTCs first.

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Raise engine speed to 3000 RPM in Park or Neutral, until cooling fan comes on. Let engine idle. Connect SCS service connector. Test-drive vehicle at 45-55 MPH for approximately 3 minutes. Decelerate for at least 3 seconds with throttle fully closed. Reduce vehicle speed to 35 MPH, and hold it there until readiness code comes on. If DTC P0420 is not indicated, system is okay at this time. Problem is intermittent. If DTC P0420 is indicated, check and/or replace warm-up three way catalyst (if equipped) and/or three way catalyst.

Isuzu Oasis S 1996 - DTC P0441 - EVAPORATIVE EMISSION (EVAP) CONTROL

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Connect SCS service connector. Test-drive vehicle for approximately 10 minutes, including gradual acceleration from 50 MPH. If DTC P0441 is not indicated, system is okay at this time. Problem is intermittent. Check for poor connections or loose wires between EVAP purge control solenoid valve connector, control box connector or PCM connectors. See WIRING DIAGRAMS section.
2. If DTC P0441 is indicated, check EVAP system vacuum hoses for proper routing, leaks or restrictions. Repair vacuum hoses as necessary. If hoses are okay, check throttle body. Clean or replace throttle body as necessary. If throttle body is okay, disconnect vacuum hose from EVAP purge flow switch and connect a vacuum gauge to hose. Install jumper wire between PCM connector terminals A10 and A15. See Fig. 4 . Start engine. Raise and hold engine speed at 1500-3000 RPM.
3. If there is less than 2.4 in. Hg vacuum, go to step 6). If there is 2.4 in. Hg. vacuum or more, turn ignition off. Reconnect hose to EVAP purge flow switch. Start engine. Raise and hold engine speed to 1500-3000 RPM. Measure voltage between PCM connector terminals C20 and A10. See Fig. 4 . If one volt or less exists, substitute a known-good PCM an d recheck. If symptom or indication goes away, replace original PCM.
4. If more than one volt exists, turn ignition off. Disconnect 2-pin EVAP purge flow switch connector. Install jumper wire between EVAP purge flow switch connector terminals No. 1 (Brown wire) and No. 2 (Black wire).
5. Turn ignition on. Measure voltage between PCM connector terminals C20 and A10. See Fig. 4 . If more than one volt exists, replace EVAP purge flow switch. If one volt or less exists, repair open in wire between PCM and purge flow switch. See WIRING DIAGRAMS section.
6. Turn ignition off. Disconnect 2-pin EVAP purge control solenoid valve connector. Turn ignition on. Measure voltage between ground and purge control solenoid connector Yellow/Black wire. If battery voltage does not exist, repair open or short in Yellow/Black wire between purge control solenoid valve and PGM-FI main relay. See WIRING DIAGRAMS section.
7. If battery voltage exists, turn ignition off. Install jumper wire between purge control solenoid valve harness connector terminals. Turn ignition on. Measure voltage between PCM connector terminals A10 and A15. See Fig. 4 . If battery voltage exists, replace EVAP purge control solenoid valve. If battery voltage does not exist, repair open in Red/Yellow wire between PCM and EVAP purge control solenoid valve. See WIRING DIAGRAMS section.

Isuzu Oasis S 1996 - DTCS P0500 & P0501 - VEHICLE SPEED SENSOR (VSS)

NOTE:

DTC P0500 indicates a malfunction in VSS circuit (M/T). DTC P0501 indicates a malfunction in VSS circuit (A/T).

1. Test-drive vehicle. Using scan tool, check vehicle speed. If correct speed is indicated, condition is intermittent. Check for poor connections or loose wires between VSS sensor and PCM connectors. See WIRING DIAGRAMS section. Repair as necessary. If correct speed is not indicated, turn ignition off.
2. Block rear wheels and set parking brake. Raise and support front of vehicle. Turn ignition on. Block right front wheel and slowly rotate left front wheel. Measure voltage between PCM connector terminals A9 and C18. See Fig. 4 . If voltage pulses between zero and 5 volts, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
3. If voltage does not pulse between zero and 5 volts, turn ignition off. Disconnect PCM connector "C". Turn ignition on. Block right front wheel and slowly rotate left front wheel. Measure voltage between PCM connector terminals A9 and C18. If voltage pulses between zero and 5 volts, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM. If voltage does not pulse between zero and 5 volts, repair wire between PCM and VSS for a short or open. See WIRING DIAGRAMS section. If wire is okay, replace VSS.

Isuzu Oasis S 1996 - DTC P0505 - IDLE CONTROL SYSTEM

NOTE:

If DTC P1508 is also stored, repair that DTC first.

1. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until cooling fan comes on. Let engine idle. Using scan tool, ensure throttle position is approximately 10 percent with throttle fully closed and engine coolant temperature is 194-205?F (90-96?C). If throttle position or engine coolant temperature are not within specification, repair faulty sensor circuit. Using scan tool, check engine speed. If engine speed is 650-750 RPM, system is okay at this time. Problem is intermittent.
2. If engine speed is 650 RPM or less, go to step 4). If engine speed not is 650 RPM or less, turn ignition off. Remove air intake duct from throttle body. Start engine and allow it to idle. Place a finger on lower port in throttle body. If engine speed drops, check engine coolant level and for air in cooling system. If cooling system is okay, replace fast idle thermovalve.
3. If engine speed does not drop, place a finger on upper port in throttle body. If engine speed does not drop, check for vacuum leaks and ensure throttle valve is completely closed. Repair as necessary. If idle speed drops, adjust idle speed to specification. See ADJUSTMENTS article. If idle speed will not adjust to specification, replace IAC valve.
4. Disconnect IAC valve connector. If engine speed does not drop or engine does not stall, replace IAC valve. If engine speed drops or engine stalls, adjust base idle speed. See ADJUSTMENTS article. If engine speed does not adjust to specification, clean throttle body ports.

Isuzu Oasis S 1996 - DTCS P1107 & P1108 - BAROMETRIC PRESSURE (BARO) SENSOR

NOTE:

DTC P1107 indicates a low voltage problem and DTC P1108 indicates a high voltage problem.

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Turn ignition on. If DTC P1107 or P1108 is indicated, substitute a known-good PCM and recheck. If DTC P1107 or P1108 is not indicated, system is functioning properly at this time. Failure is intermittent.

Isuzu Oasis S 1996 - DTC P1297 - ELECTRICAL LOAD DETECTOR (ELD)

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. Turn headlights on. If DTC P1297 is not indicated, system is okay at this time. Failure is intermittent. Check for poor connections or loose wires at ELD and PCM connectors. See WIRING DIAGRAMS section. If DTC P1297 is indicated, turn ignition and headlights off.
2. Disconnect ELD connector. Turn ignition on. Measure voltage between ELD connector terminal No. 3 (IG1) and ground. See Fig. 9 . If battery voltage exists, go to next step. If battery voltage does not exist, repair open in wire between underdash fuse/relay box and ELD. See WIRING DIAGRAMS section.
3. Measure voltage between ELD connector terminal No. 2 (EL) and ground. See Fig. 9 . If approximately 5 volts exists, replace ELD. If approximately 5 volts does not exist, turn ignition off.
4. Disconnect PCM connector "D". See Fig. 4 . Check for continuity between PCM connector terminal D16 and ground. If continuity exists, repair short in wire between PCM connector terminal D16 and ELD. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or problem goes away, replace original PCM.

Fig. 9: Isuzu Oasis S 1996 - Component Locations - Identifying Electrical Load Detector (ELD) Connector (Oasis)

Isuzu Oasis S 1996 - DTC P1298 - ELECTRICAL LOAD DETECTOR (ELD)

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine and turn headlights on. If DTC P1298 is not indicated, system is okay at this time. Failure is intermittent. Check for poor connections or loose wires at ELD and PCM connectors. See WIRING DIAGRAMS section. If DTC P1298 is indicated, turn ignition and headlights off.
2. Disconnect ELD connector. Check for continuity between ELD connector terminal No. 1 (GND) and ground. See Fig. 9 . If continuity does not exist, repair open in wire between ELD and ground. See WIRING DIAGRAMS section. If there is continuity, reconnect ELD connector and go to step 4).
3. Check for continuity between ELD connector terminal No. 3 (EL) and PCM connector terminal D16. See Fig. 4 . If continuity exists, reconnect ELD and go to next step. If continuity does not exist, repair open in wire between PCM terminal D16 and ELD. See WIRING DIAGRAMS section.
4. Start engine and allow it to idle. While measuring voltage between PCM terminals A9 and D16, turn headlights on. If voltage does not drop, replace ELD. If voltage drops, substitute a known-good PCM and recheck. If symptom or problem goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P1359 - CRANKSHAFT POSITION/TOP DEAD CENTER (CKP/TDC) SENSOR

NOTE:

DTC P1359 indicates a malfunction in CKP/TDC sensor circuit.

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. If DTC P1359 is indicated, go to next step. If DTC P1359 is not indicated, system is functioning properly at this time. Failure is intermittent. Repair as necessary.
2. Check for poor connections or loose wires between CKP/TDC sensor connector and PCM connector. See WIRING DIAGRAMS section. Repair as necessary. If wires and connections are okay, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTCS P1381 & P1382 - CYLINDER POSITION - (CYP) SENSOR

NOTE:

DTC P1381 indicates intermittent interruption in CYP sensor circuit. DTC P1382 indicates no signal in CYP sensor circuit.

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine. If DTCs P1381 and/or P1382 are not present, system is okay at this time. Failure is intermittent. Check for poor connections or loose wires between CYP connector and PCM connectors. See WIRING DIAGRAMS section. If DTCs P1381 and/or P1382 are present, turn ignition off. Disconnect distributor connector.
2. Measure resistance between sensor terminals No. 4 (CYPP) and No. 5 (CYPM). See Fig. 10 . Resistance should be 800-1500 ohms.
3. If resistance is not as specified, replace distributor. If resistance is as specified, check for continuity between ground and CYP sensor terminals No. 2 and 4 individually. See Fig. 10 . If continuity exists, replace distributor.
4. If continuity exists, reconnect distributor connector. Disconnect PCM connector "C". See Fig. 4 . Measure resistance between PCM connector terminals C4 and C14 If resistance is not 800-1500 ohms, repair open in appropriate wire(s). See WIRING DIAGRAMS section.
5. If resistance is 800-1500 ohms, check for continuity between ground and PCM connector terminals C4. If continuity exists, repair short in appropriate wire(s). See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or problem goes away, replace original PCM.

Fig. 10: Isuzu Oasis S 1996 - Component Locations - Identifying CYP Sensor Connector (Oasis)

Isuzu Oasis S 1996 - DTC P1459 - EVAP CONTROL

1. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES . Connect SCS service connector. Let engine idle. If DTC P1459 is not indicated, system is operating properly at this time. Problem is intermittent. Check for poor connections or loose wires at EVAP purge flow switch, control box and PCM connectors. See WIRING DIAGRAMS section.
2. If DTC P1459 is indicated, turn ignition off. Check EVAP system vacuum hoses for proper routing, leaks or restrictions. Repair vacuum hoses as necessary. If vacuum hoses are okay, disconnect 2-pin purge flow switch. Check for continuity between PCM terminals A10 and C10. See Fig. 4 . If continuity does not exist, replace EVAP purge flow switch.
3. If continuity exists, disconnect PCM connector "C". Check for continuity between EVAP purge flow switch harness connector terminals (Brown and Black wires). If there is continuity, repair Brown wire for a short between PCM and EVAP purge flow switch. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P1491 - EGR SYSTEM

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Connect SCS service connector. Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator cooling fan comes on. Drive vehicle for approximately 10 minutes. Maintain engine speed at 1700-2500 RPM. If DTC P1491 is not indicated, system is okay at this time. Problem is intermittent. Check for poor connections or loose wires between EGR valve connector and PCM connectors. See WIRING DIAGRAMS section.
2. If DTC P1491 is indicated, disconnect vacuum hose (No. 16) from EGR valve. Connect vacuum pump/gauge to hose. Start engine and let it idle. If vacuum does not exist, go to step 4). If vacuum exists, disconnect EGR solenoid valve 2-pin connector. Recheck hose (No. 16) for vacuum. If vacuum exists, check EGR system hose routing. If hose routing is okay, replace EGR control solenoid valve. If vacuum does not exist, turn ignition off. Disconnect PCM connector "A". See Fig. 4 .
3. Check for continuity between ground and EGR control solenoid harness connector Red wire. If there is continuity, repair short in Red wire between PCM and EGR control solenoid. See WIRING DIAGRAMS section. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
4. Connect vacuum pump/gauge to EGR valve. engine idling, apply 8 in. Hg vacuum to EGR valve. If engine does not stall or run rough, or EGR valve does not hold vacuum, replace EGR valve. If engine stalls or runs rough, and EGR valve holds vacuum, turn ignition off. Disconnect EGR control solenoid connector. Turn ignition on.
5. Measure voltage between ground and EGR control solenoid connector Black/Yellow wire. If battery voltage does not exist, repair open in appropriate wire between EGR control solenoid and power source. See WIRING DIAGRAMS section.
6. If battery voltage exists, reconnect vacuum pump/gauge to vacuum hose (No. 16). Start engine and let it idle. Jumper positive battery terminal to left EGR control solenoid connector terminal. While observing vacuum gauge, connect right EGR control solenoid connector terminal to negative battery terminal.
7. If there is not approximately 8 in. Hg vacuum within one second, go to step 9). If there is approximately 8 in. Hg vacuum within one second, turn ignition off. Reconnect EGR control solenoid valve connector. Reconnect vacuum hose (No. 16) to EGR valve.
8. Start engine and let it idle. Jumper PCM terminal A7 to terminal A10. If engine does not run rough or stall, repair open in Red wire between PCM and EGR control solenoid. If engine runs rough or stalls, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
9. Turn ignition off. Inspect vacuum hoses for proper routing, leaks or restrictions. Repair hoses as necessary. If hoses are okay, disconnect lower hose on EGR control solenoid valve and connect a vacuum gauge to hose. Start engine and let it idle. If there is approximately 7.87 in. Hg vacuum, replace EGR control solenoid valve. If there is not approximately 7.87 in. Hg vacuum, repair vacuum hose between intake manifold and EGR vacuum control valve, or replace EGR vacuum control valve.
10. Turn ignition off. Inspect vacuum hoses for proper routing, leaks or restrictions. Repair hoses as necessary. If hoses are okay, replace EGR control solenoid valve.
11. Turn ignition off and disconnect EGR solenoid valve connector. Disconnect PCM connector "A". Check for continuity between PCM connector terminal A7 (Red wire) and EGR solenoid valve harness connector Red wire. If continuity does not exist, repair open in Red wire between PCM and EGR control solenoid valve harness connector. See WIRING DIAGRAMS section. If continuity exists, check for continuity between ground and EGR control solenoid valve harness connector Red wire. See WIRING DIAGRAMS section.
12. If continuity exists, repair short to ground in Red wire. See WIRING DIAGRAMS section. If continuity does not exist, check for continuity between ground and EGR control solenoid valve harness connector Black wire. If continuity does not exist, repair open in Black wire between ground and EGR control solenoid valve harness connector. See WIRING DIAGRAMS section. If continuity exists, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P1498 - EXHAUST GAS RECIRCULATION (EGR) SYSTEM

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Turn ignition on. If DTC P1498 is not indicated, system is okay at this time. Problem is intermittent. Check for poor connections or loose wires between EGR valve lift harness connector and PCM connector. See WIRING DIAGRAMS section. If DTC P1498 is indicated, turn ignition off. Disconnect EGR valve lift sensor connector.
2. Turn ignition on. Measure voltage between EGR valve lift sensor harness Green/Blue wire and Yellow/Blue wire. If approximately 5 volts exists, replace EGR valve.
3. If approximately 5 volts does not exist, measure voltage between PCM connector terminals D10 and D11. See Fig. 4 . If there is approximately 5 volts, repair open in wire between PCM and EGR valve lift sensor. See WIRING DIAGRAMS section. If approximately 5 volts does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P1508 - IDLE AIR CONTROL (IAC) VALVE

1. Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Start engine and allow to idle for at least 30 seconds. If DTC P1508 is not indicated, system is okay at this time. Problem is intermittent. Check for poor connections or loose wires between IAC valve connector and PCM connector. See WIRING DIAGRAMS section. If DTC P1508 is indicated, turn ignition off. Disconnect IAC valve connector.
2. Turn ignition on. Measure voltage between ground and IAC valve harness connector Yellow/Black wire. If battery voltage does not exist, repair open in Yellow/Black wire between IAC valve harness connector and PGM-FI main relay. See WIRING DIAGRAMS section. If battery voltage exists, turn ignition off and reconnect IAC valve connector. Disconnect PCM connector "A". See Fig. 4 . Turn ignition on.
3. Measure voltage between ground and PCM connector A12. If battery voltage does not exist, repair open or short in wire between IAC valve harness connector and PCM connector. See WIRING DIAGRAMS section. If battery voltage exists, momentarily connect PCM connector terminals A10 and A12 several times. See Fig. 4 . If IAC valve does not click, replace IAC valve. If IAC valve clicks, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Isuzu Oasis S 1996 - DTC P1607 - PCM INTERNAL CIRCUIT

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES. Turn ignition on. Wait 3 seconds. If DTC P1607 is not indicated, system is okay at this time. Problem is intermittent. If DTC P1607 is indicated, substitute a known-good PCM and recheck. If symptom or problem goes away, replace original PCM.

Isuzu Oasis S 1996 - SUMMARY

If no hard trouble codes (or only pass codes) are present, driveability symptoms exist or intermittent Diagnostic Trouble Codes (DTCs) exist, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedure.

Isuzu Oasis S 1996 - WIRING DIAGRAMS

Fig. 11: Isuzu Oasis S 1996 - Component Locations - Wiring Diagram (Oasis 2.2L - 1 Of 3)

Fig. 12: Isuzu Oasis S 1996 - Component Locations - Wiring Diagram (Oasis 2.2L - 2 Of 3)

Fig. 13: Isuzu Oasis S 1996 - Component Locations - Wiring Diagram (Oasis 2.2L - 3 Of 3)