Honda Civic Si 1993 - 1993 ENGINE PERFORMANCE Self-Diagnostics

Honda Civic Si 1993 - INTRODUCTION

If no faults were found while performing BASIC TESTING , 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 in the ENGINE PERFORMANCE Section for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

Honda Civic Si 1993 - 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 TROUBLE CODE CHARTS. 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.

Honda Civic Si 1993 - 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 ECM memory. If related fault does not reoccur within 50 starter operations, related DTC will be erased from control unit memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article in the ENGINE PERFORMANCE Section.

Honda Civic Si 1993 - MALFUNCTION INDICATOR LIGHT (MIL)

All models are equipped with an MIL. As a bulb check, light illuminates 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 ECM memory. Not all trouble codes will activate MIL. If MIL is on and no DTCs are in memory, see TESTS W/O CODES article in the ENGINE PERFORMANCE Section.

Honda Civic Si 1993 - RETRIEVING CODES

With ignition off, insert jumper wire in service check connector terminals, located behind right side of dash. See Fig. 1 . Turn ignition switch to ON position. 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 TROUBLE CODE DEFINITION table and proceed to appropriate TROUBLE CODE CHART for testing. 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.

Fig. 1: Honda Civic Si 1993 - Component Locations - Locating Service Check Connectors, Civic & Civic Del Sol

Honda Civic Si 1993 - DIAGNOSTIC TROUBLE CODE DEFINITION

Honda Civic Si 1993 DIAGNOSTIC TROUBLE CODE IDENTIFICATION

Code (1)	System Affected	Probable Cause
0	ECM	No Signal To ECM
1	Oxygen Sensor (O2S) (Federal Models D15B8)	Problem In O2S Circuit
1	Heated Oxygen Sensor (HO2S) (Except Fed. D15B8)	Problem In HO2S Circuit
3	MAP Sensor	Electrical Problem In MAP Sensor
4	Crank Angle Sensor (CKP)	Open Or Shorted Signal Circuit
5	MAP Sensor (D15B7)	Mechanical Problem In MAP Sensor
5	MAP Sensor (Except D15B7)	Mechanical Problem In MAP Sensor
6	Engine Coolant Temperature (ECT) Sensor	Open Or Shorted Signal Circuit
7	Throttle Position (TP) Sensor	Open Or Shorted Signal Circuit
8	Crank Angle Sensor (TDC)	Open Or Shorted Signal Circuit
9	Crank Angle Sensor (CYP)	Open Or Shorted Signal Circuit
10	Intake Air Temperature(IAT)	Problem With Sensor
12	EGR System	No EGR Action
13	Barometric Pressure (BARO) Sensor	Problem With PA Circuit
14	Idle Air Control(IAC) Valve	Open Or Shorted Signal Circuit
15	Ignition Output Signal	Electrical Problem In Signal Circuit
16	Fuel Injector	Problem In Fuel Injector Circuit
17	Vehicle Speed Sensor (VSS)	Open Or Shorted Signal Circuit
19	A/T Lock-Up Control Solenoid Valve	Problem In Lock-Up Solenoid Circuit
20	Electrical Load Detector (ELD)	Problem With ELD Circuit
21	Spool Solenoid Valve	Problem With VTEC Spool Solenoid Circuit
22	VTEC Oil Pressure Switch	Problem In VTEC Oil Pressure Switch Circuit
41	Heated Oxygen Sensor (HO2S) Heater (Federal Models D15Z1)	Problem With HO2S Circuit
41	Heated Oxygen Sensor (HO2S) Heater (Except Fed. D15Z1)	Problem With HO2S Circuit
43	Fuel Supply System (D15B8)	Problem With HO2S Circuit Or Fuel System
48	Heated Oxygen Sensor (HO2S) (D15Z1)	Problem With HO2S Circuit
(1) If codes other than these are indicated, repeat self-diagnosis. If code(s) reappear, substitute a known good ECM, and recheck codes. If code(s) clear, replace ECM.

Honda Civic Si 1993 - ECM 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 ECM reset, the radio will not function until code is entered.

To reset ECM, remove BACK UP fuse (CLOCK/RADIO fuse on Prelude) from underhood fuse/relay block. Leave fuse out for 10 seconds to reset ECM.

Honda Civic Si 1993 - ECM LOCATION

The ECM is located in passenger side kick panel. See Fig. 1 .

Honda Civic Si 1993 - SUMMARY

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

Honda Civic Si 1993 - DIAGNOSTIC TROUBLE CODE CHARTS

NOTE:

In the following diagnostic trouble code charts, illustrations and schematics are courtesy of American Honda Motor Co., Inc.

Honda Civic Si 1993 - Using Diagnostic Trouble Code Charts

To use DIAGNOSTIC TROUBLE CODE CHARTS, see RETRIEVING CODES under SELF-DIAGNOSTIC SYSTEM. After codes have been recorded, proceed to appropriate DIAGNOSTIC TROUBLE CODE CHART.

When directed by chart to install ECM test harness, turn ignition off. Connect ECM Test Harness (07LAJ-PT3010A ) between ECM and connector. See Fig. 2 . Follow code chart directions.

Fig. 2: Honda Civic Si 1993 - Component Locations - Installing PGM-FI ECM Test Harness & Identifying Terminals

Honda Civic Si 1993 - CODE/NO CODE - NO START TROUBLE SHOOTING

Fig. 3: Honda Civic Si 1993 - Component Locations - Flowchart, No Start Trouble Shooting (1 of 5)

Fig. 4: Honda Civic Si 1993 - Component Locations - Flowchart, No Start Trouble Shooting (2 of 5)

Fig. 5: Honda Civic Si 1993 - Component Locations - Flowchart, No Start Trouble Shooting (3 of 5)

Fig. 6: Honda Civic Si 1993 - Component Locations - Flowchart, No Start Trouble Shooting (4 of 5)

Fig. 7: Honda Civic Si 1993 - Component Locations - Flowchart, No Start Trouble Shooting (5 of 5)

Honda Civic Si 1993 - CODE 1 - D15B8 - OXYGEN SENSOR (O2S) CIRCUIT (FEDERAL MODEL ONLY)

Fig. 8: Honda Civic Si 1993 - Component Locations - Code 1 Flowchart, D15B8 Oxygen Sensor Circuit (Fed.)(1 of 2)

Fig. 9: Honda Civic Si 1993 - Component Locations - Code 1 Flowchart, D15B8 Oxygen Sensor Circuit (Fed.)(2 of 2)

Honda Civic Si 1993 - CODE 1 - HEATED OXYGEN SENSOR(HO2S) CIRCUIT (EXC. FED. D15B8)

Fig. 10: Honda Civic Si 1993 - Component Locations - Code 1 Flowchart, Heated Oxygen Sensor Cir.(Exc. Fed. D15B8)

Honda Civic Si 1993 - CODE 3 - MAP SENSOR CIRCUIT

Fig. 11: Honda Civic Si 1993 - Component Locations - Code 3 Flowchart, MAP Sensor Circuit (1 of 3)

Fig. 12: Honda Civic Si 1993 - Component Locations - Code 3 Flowchart, MAP Sensor Circuit (2 of 3)

Fig. 13: Honda Civic Si 1993 - Component Locations - Code 3 Flowchart, MAP Sensor Circuit (3 of 3)

Honda Civic Si 1993 - CODE 4, 8 AND/OR 9 - TDC/CKP/CYP SENSOR

Fig. 14: Honda Civic Si 1993 - Component Locations - Code 4, 8 and/or 9 Flowchart, TDC/CKP/CYP Sensor (1 of 2)

Fig. 15: Honda Civic Si 1993 - Component Locations - Code 4, 8 and/or 9 Flowchart, TDC/CKP/CYP Sensor (2 of 2)

Honda Civic Si 1993 - CODE 5 - EXCEPT D15B7 - MAP SENSOR CIRCUIT

Fig. 16: Honda Civic Si 1993 - Component Locations - Code 5 Flowchart, MAP Sensor Circuit (Exc. D15B7) (1 of 2)

Fig. 17: Honda Civic Si 1993 - Component Locations - Code 5 Flowchart, MAP Sensor Circuit (Exc. D15B7) (2 of 2)

Honda Civic Si 1993 - CODE 5 - D15B7 - MAP SENSOR CIRCUIT

Fig. 18: Honda Civic Si 1993 - Component Locations - Code 5 Flowchart, MAP Sensor Circuit (D15B7) (1 of 2)

Fig. 19: Honda Civic Si 1993 - Component Locations - Code 5 Flowchart, MAP Sensor Circuit (D15B7) (2 of 2)

Honda Civic Si 1993 - CODE 6 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Fig. 20: Honda Civic Si 1993 - Component Locations - Code 6 Flowchart, Engine Coolant Temperature Sensor (1 of 2)

Fig. 21: Honda Civic Si 1993 - Component Locations - Code 6 Flowchart, Engine Coolant Temperature Sensor (2 of 2)

Honda Civic Si 1993 - CODE 7 - THROTTLE POSITION (TP) SENSOR

Fig. 22: Honda Civic Si 1993 - Component Locations - Code 7 Flowchart, Throttle Position Sensor (1 of 2)

Fig. 23: Honda Civic Si 1993 - Component Locations - Code 7 Flowchart, Throttle Position Sensor (2 of 2)

Honda Civic Si 1993 - CODE 10 - INTAKE AIR TEMPERATURE (IAT) SENSOR

Fig. 24: Honda Civic Si 1993 - Component Locations - Code 10 Flowchart, Intake Air Temperature Sensor (1 of 2)

Fig. 25: Honda Civic Si 1993 - Component Locations - Code 10 Flowchart, Intake Air Temperature Sensor (2 of 2)

Honda Civic Si 1993 - CODE 12 - EGR SYSTEM

Fig. 26: Honda Civic Si 1993 - Component Locations - Code 12 Flowchart, EGR System (1 of 5)

Fig. 27: Honda Civic Si 1993 - Component Locations - Code 12 Flowchart, EGR System (2 of 5)

Fig. 28: Honda Civic Si 1993 - Component Locations - Code 12 Flowchart, EGR System (3 of 5)

Fig. 29: Honda Civic Si 1993 - Component Locations - Code 12 Flowchart, EGR System (4 of 5)

Fig. 30: Honda Civic Si 1993 - Component Locations - Code 12 Flowchart, EGR System (5 of 5)

Honda Civic Si 1993 - CODE 13 - BAROMETRIC PRESSURE (BARO) SENSOR

Fig. 31: Honda Civic Si 1993 - Component Locations - Code 13 Flowchart, Barometric Pressure Sensor

Honda Civic Si 1993 - CODE 14 - IDLE AIR CONTROL (IAC) VALVE

Fig. 32: Honda Civic Si 1993 - Component Locations - Code 14 Flowchart, Idle Air Control Valve (1 of 2)

Fig. 33: Honda Civic Si 1993 - Component Locations - Code 14 Flowchart, Idle Air Control Valve (2 of 2)

Honda Civic Si 1993 - CODE 15 - IGNITION OUTPUT SIGNAL

Fig. 34: Honda Civic Si 1993 - Component Locations - Code 15 Flowchart, Ignition Output Signal (1 of 2)

Fig. 35: Honda Civic Si 1993 - Component Locations - Code 15 Flowchart, Ignition Output Signal (2 of 2)

Honda Civic Si 1993 - CODE 16 - FUEL INJECTORS

Fig. 36: Honda Civic Si 1993 - Component Locations - Code 16 Flowchart, Fuel Injectors (1 of 3)

Fig. 37: Honda Civic Si 1993 - Component Locations - Code 16 Flowchart, Fuel Injectors (2 of 3)

Fig. 38: Honda Civic Si 1993 - Component Locations - Code 16 Flowchart, Fuel Injectors (3 of 3)

Honda Civic Si 1993 - CODE 17 - VEHICLE SPEED SENSOR (VSS)

Fig. 39: Honda Civic Si 1993 - Component Locations - Code 17 Flowchart, Vehicle Speed Sensor (1 of 2)

Fig. 40: Honda Civic Si 1993 - Component Locations - Code 17 Flowchart, Vehicle Speed Sensor (2 of 2)

Honda Civic Si 1993 - CODE 19 - LOCK-UP CONTROL SOLENOID VALVE

Fig. 41: Honda Civic Si 1993 - Component Locations - Code 19 Flowchart, Lock-Up Control Solenoid Valve (1 of 2)

Fig. 42: Honda Civic Si 1993 - Component Locations - Code 19 Flowchart, Lock-Up Control Solenoid Valve (2 of 2)

Honda Civic Si 1993 - CODE 20 - ELECTRICAL LOAD DETECTOR (ELD)

Fig. 43: Honda Civic Si 1993 - Component Locations - Code 20 Flowchart, Electrical Load Detector (1 of 2)

Fig. 44: Honda Civic Si 1993 - Component Locations - Code 20 Flowchart, Electrical Load Detector (2 of 2)

Honda Civic Si 1993 - CODE 21 - VTEC SOLENOID VALVE

Fig. 45: Honda Civic Si 1993 - Component Locations - Code 21 Flowchart, VTEC Solenoid Valve (1 of 2)

Fig. 46: Honda Civic Si 1993 - Component Locations - Code 21 Flowchart, VTEC Solenoid Valve (2 of 2)

Honda Civic Si 1993 - CODE 22 - VTEC PRESSURE SWITCH

Fig. 47: Honda Civic Si 1993 - Component Locations - Code 22 Flowchart, VTEC Pressure Switch (1 of 3)

Fig. 48: Honda Civic Si 1993 - Component Locations - Code 22 Flowchart, VTEC Pressure Switch (2 of 3)

Fig. 49: Honda Civic Si 1993 - Component Locations - Code 22 Flowchart, VTEC Pressure Switch (3 of 3)

Honda Civic Si 1993 - CODE 41 - HEATED OXYGEN SENSOR(HO2S) HEATER (EXC. FED. D15Z1)

Fig. 50: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (Exc. Fed. D15Z1)(1 of 3)

Fig. 51: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (Exc. Fed. D15Z1)(2 of 3)

Fig. 52: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (Exc. Fed. D15Z1)(3 of 3)

Honda Civic Si 1993 - CODE 41 - HEATED OXYGEN SENSOR (HO2S) HEATER (D15Z1 FED.)

Fig. 53: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (D15Z1 Fed.) (1 of 3)

Fig. 54: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (D15Z1 Fed.) (2 of 3)

Fig. 55: Honda Civic Si 1993 - Component Locations - Code 41 Flowchart, HO2S Heater (D15Z1 Fed.) (3 of 3)

Honda Civic Si 1993 - CODE 43 - D15B8 - HEATED OXYGEN SENSOR (HO2S) HEATER (FED.)

Fig. 56: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, HO2S Heater (D15B8 Fed. Only)(1 of 2)

Fig. 57: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, HO2S Heater (D15B8 Fed. Only)(2 of 2)

Honda Civic Si 1993 - CODE 48 - D15Z1 HEATED OXYGEN SENSOR (HO2S) (FED.)

Fig. 58: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(1 of 6)

Fig. 59: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(2 of 6)

Fig. 60: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(3 of 6)

Fig. 61: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(4 of 6)

Fig. 62: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(5 of 6)

Fig. 63: Honda Civic Si 1993 - Component Locations - Code 43 Flowchart, Heated Oxygen Sensor (D15Z1 Fed.)(6 of 6)