Honda Civic EX 1994 - 1994 ENGINE PERFORMANCE Self-Diagnostics

Honda Civic EX 1994 - 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 for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

Honda Civic EX 1994 - 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 EX 1994 - 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.

Honda Civic EX 1994 - 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, problem may be intermittent. See INTERMITTENTS in TESTS W/O CODES article.

Honda Civic EX 1994 - RETRIEVING CODES

Turn ignition off. Insert jumper wire in service check connector terminals, located behind right side of dash. See Fig. 1 .

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 table and proceed to appropriate DIAGNOSTIC TROUBLE CODE CHARTS 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 EX 1994 - Component Locations - Locating Service Check Connector

Honda Civic EX 1994 - DIAGNOSTIC TROUBLE CODE DEFINITION

Honda Civic EX 1994 DIAGNOSTIC TROUBLE CODE IDENTIFICATION

Code (1)	System Affected	Probable Cause
0	ECM	No Signal To ECM
1	Oxygen Sensor (O2S) (D15B8 Federal Model)	Problem In HO2S Circuit
1	Heated Oxygen Sensor (HO2S) (Except D15B8 Fed. Model)	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	Electrical 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 (Civic & Civic Del Sol)	Problem In Lock-Up Solenoid Circuit
20 (2)	Electrical Load Detector (ELD)	Problem With ELD Circuit
21	Spool Solenoid Valve (Civic & Civic Del Sol)	Problem With VTEC Spool Solenoid Circuit
22	VTEC Oil Pressure Switch	Problem In VTEC Oil Pressure Switch Circuit
41	Heated Oxygen Sensor (HO2S) Heater (D15Z1 Federal Model)	Problem With HO2S Circuit
41	Heated Oxygen Sensor (HO2S) Heater (Except D15Z1 Fed. Model)	Problem With HO2S Circuit
43	Fuel Supply System (Except D15B8 Calif. Model)	Problem With HO2S Circuit Or Fuel System
48	Heated Oxygen Sensor (HO2S) (D15Z1 Federal Model)	HO2S Circuit Fault
(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. (2) MIL does not come on when there is a malfunction in ELD circuit, but code is stored in ECM memory.

Honda Civic EX 1994 - 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 (clear codes), remove BACK UP fuse from underhood fuse/relay block. Leave fuse out for 10 seconds to reset ECM.

Honda Civic EX 1994 - ECM LOCATION

ECM is located in passenger side kick panel.

Honda Civic EX 1994 - 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 EX 1994 - 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 EX 1994 - Component Locations - Installing PGM-FI ECM Test Harness & Identifying Terminals

NOTE:

The Following Flow Charts are Courtesy of American Honda Motors Co., Inc.

Honda Civic EX 1994 - CODE/NO CODE - NO START TROUBLE SHOOTING

Fig. 3: Honda Civic EX 1994 - Component Locations - Code/No Code Flow Chart (1 of 5) Code/No Code - No Start Trouble Shooting

Fig. 4: Honda Civic EX 1994 - Component Locations - Code/No Code Flow Chart (2 of 5) Code/No Code - No Start Trouble Shooting

Fig. 5: Honda Civic EX 1994 - Component Locations - Code/No Code Flow Chart (3 of 5) Code/No Code - No Start Trouble Shooting

Fig. 6: Honda Civic EX 1994 - Component Locations - Code/No Code Flow Chart (4 of 5) Code/No Code - No Start Trouble Shooting

Fig. 7: Honda Civic EX 1994 - Component Locations - Code/No Code Flow Chart (5 of 5) Code/No Code - No Start Trouble Shooting

Honda Civic EX 1994 - CODE 1 - OXYGEN SENSOR (O2S) CIRCUIT D15B8 FEDERAL MODEL

Fig. 8: Honda Civic EX 1994 - Component Locations - Code 1 Flow Chart (1 of 2) Oxygen Sensor (O2S) Circuit D15B8 Federal Model

Fig. 9: Honda Civic EX 1994 - Component Locations - Code 1 Flow Chart (2 of 2) Oxygen Sensor (O2S) Circuit D15B8 Federal Model

Honda Civic EX 1994 - CODE 1 - HEATED OXYGEN SENSOR (HO2S) CIRCUIT ALL ENGINES EXCEPT D15B8 FEDERAL MODEL

Fig. 10: Honda Civic EX 1994 - Component Locations - Code 1 Flow Chart Heated Oxygen Sensor (HO2S) Circuit

Honda Civic EX 1994 - CODE 3 - MAP SENSOR CIRCUIT

Fig. 11: Honda Civic EX 1994 - Component Locations - Code 3 Flow Chart (1 of 3) MAP Sensor Circuit

Fig. 12: Honda Civic EX 1994 - Component Locations - Code 3 Flow Chart (2 of 3) MAP Sensor Circuit

Fig. 13: Honda Civic EX 1994 - Component Locations - Code 3 Flow Chart (3 of 3) MAP Sensor Circuit

Honda Civic EX 1994 - CODE 4, 8 AND/OR 9 TDC/CKP/CYP SENSOR

Fig. 14: Honda Civic EX 1994 - Component Locations - Code 4, 8 AND/OR 9 Flow Chart (1 of 2) TDC/CKP/CYP Sensor

Fig. 15: Honda Civic EX 1994 - Component Locations - Code 4, 8 AND/OR 9 Flow Chart (2 of 2) TDC/CKP/CYP Sensor

Honda Civic EX 1994 - CODE 5 - MAP SENSOR CIRCUIT

Fig. 16: Honda Civic EX 1994 - Component Locations - Code 5 Flow Chart (1 of 2) MAP Sensor Circuit

Fig. 17: Honda Civic EX 1994 - Component Locations - Code 5 Flow Chart (2 of 2) MAP Sensor Circuit

Honda Civic EX 1994 - CODE 6 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Fig. 18: Honda Civic EX 1994 - Component Locations - Code 6 Flow Chart (1 of 2) Engine Coolant Temperature (ECT) Sensor

Fig. 19: Honda Civic EX 1994 - Component Locations - Code 6 Flow Chart (1 of 2) Engine Coolant Temperature (ECT) Sensor

Honda Civic EX 1994 - CODE 7 - THROTTLE POSITION (TP) SENSOR

Fig. 20: Honda Civic EX 1994 - Component Locations - Code 7 Flow Chart (1 of 2) Throttle Position (TP) Sensor

Fig. 21: Honda Civic EX 1994 - Component Locations - Code 7 Flow Chart (2 of 2) Throttle Position (TP) Sensor

Honda Civic EX 1994 - CODE 10 - INTAKE AIR TEMPERATURE (IAT) SENSOR

Fig. 22: Honda Civic EX 1994 - Component Locations - Code 10 Flow Chart (1 of 2) Intake Air Temperature (IAT) Sensor

Fig. 23: Honda Civic EX 1994 - Component Locations - Code 10 Flow Chart (2 of 2) Intake Air Temperature (IAT) Sensor

Honda Civic EX 1994 - CODE 12 - EGR SYSTEM D15Z1 ENGINE ONLY

Fig. 24: Honda Civic EX 1994 - Component Locations - Code 12 Flow Chart (1 of 5) EGR System d15z1 Engine Only

Fig. 25: Honda Civic EX 1994 - Component Locations - Code 12 Flow Chart (2 of 5) EGR System D15Z1 Engine Only

Fig. 26: Honda Civic EX 1994 - Component Locations - Code 12 Flow Chart (3 of 5) EGR System D15Z1 Engine Only

Fig. 27: Honda Civic EX 1994 - Component Locations - Code 12 Flow Chart (4 of 5) EGR System D15Z1 Engine Only

Fig. 28: Honda Civic EX 1994 - Component Locations - Code 12 Flow Chart (5 of 5) EGR System D15Z1 Engine Only

Honda Civic EX 1994 - CODE 13 - BAROMETRIC PRESSURE (BARO) SENSOR

Fig. 29: Honda Civic EX 1994 - Component Locations - Code 13 Flow Chart Barometric Pressure (BARO) Sensor

Honda Civic EX 1994 - CODE 14 - IDLE AIR CONTROL (IAC) VALVE

Fig. 30: Honda Civic EX 1994 - Component Locations - Code 14 Flow Chart (1 of 2) Idle Air Control (IAC) Valve

Fig. 31: Honda Civic EX 1994 - Component Locations - Code 14 Flow Chart (2 of 2) Idle Air Control (IAC) Valve

Honda Civic EX 1994 - CODE 15 - IGNITION OUTPUT SIGNAL

Fig. 32: Honda Civic EX 1994 - Component Locations - Code 15 Flow Chart (1 of 2) Ignition Output Signal

Fig. 33: Honda Civic EX 1994 - Component Locations - Code 15 Flow Chart (2 of 2) Ignition Output Signal

Honda Civic EX 1994 - CODE 16 - FUEL INJECTORS

Fig. 34: Honda Civic EX 1994 - Component Locations - Code 16 Flow Chart (1 of 3) Fuel Injectors

Fig. 35: Honda Civic EX 1994 - Component Locations - Code 16 Flow Chart (2 of 3) Fuel Injectors

Fig. 36: Honda Civic EX 1994 - Component Locations - Code 16 Flow Chart (3 of 3) Fuel Injectors)

Honda Civic EX 1994 - CODE 17 - VEHICLE SPEED SENSOR (VSS)

Fig. 37: Honda Civic EX 1994 - Component Locations - Code 17 Flow Chart (1 of 2) Vehicle Speed Sensor (VSS)

Fig. 38: Honda Civic EX 1994 - Component Locations - Code 17 Flow Chart (1 of 2) Vehicle Speed Sensor (VSS)

Honda Civic EX 1994 - CODE 19 - LOCK-UP CONTROL SOLENOID VALVE

Fig. 39: Honda Civic EX 1994 - Component Locations - Code 19 Flow Chart (1 of 2) Lock-up Control Solenoid Valve

Fig. 40: Honda Civic EX 1994 - Component Locations - Code 19 Flow Chart (2 of 2) Lock-up Control Solenoid Valve

Honda Civic EX 1994 - CODE 20 - ELECTRICAL LOAD DETECTOR (ELD)

Fig. 41: Honda Civic EX 1994 - Component Locations - Code 20 Flow Chart (1 of 2) Electrical Load Detector (ELD)

Fig. 42: Honda Civic EX 1994 - Component Locations - Code 20 Flow Chart (2 of 2) Electrical Load Detector (ELD)

Honda Civic EX 1994 - CODE 21 - VTEC SOLENOID VALVE

Fig. 43: Honda Civic EX 1994 - Component Locations - Code 21 Flow Chart (1 of 2) VTEC Solenoid Valve

Fig. 44: Honda Civic EX 1994 - Component Locations - Code 21 Flow Chart (2 of 2) VTEC Solenoid Valve

Honda Civic EX 1994 - CODE 22 - VTEC PRESSURE SWITCH

Fig. 45: Honda Civic EX 1994 - Component Locations - Code 22 Flow Chart (1 of 3) VTEC Pressure Switch

Fig. 46: Honda Civic EX 1994 - Component Locations - Code 22 Flow Chart (2 of 3) VTEC Pressure Switch

Fig. 47: Honda Civic EX 1994 - Component Locations - Code 22 Flow Chart (3 of 3) VTEC Pressure Switch

Honda Civic EX 1994 - CODE 41 - HEATED OXYGEN SENSOR (HO2S) HEATER ALL MODELS EXCEPT D15Z1 FEDERAL MODEL

Fig. 48: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (1 of 3) Heated Oxygen Sensor (HO2S) Heater All Except D15Z1 Federal Model

Fig. 49: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (2 of 3) Heated Oxygen Sensor (HO2S) Heater All Except D15Z1 Federal Model

Fig. 50: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (3 of 3) Heated Oxygen Sensor (HO2S) Heater All Except D15Z1 Federal Model

Honda Civic EX 1994 - CODE 41 - HEATED OXYGEN SENSOR (HO2S) HEATER D15Z1 FEDERAL MODEL

Fig. 51: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (1 of 3) Heated Oxygen Sensor (HO2S) Heater D15Z1 Federal Model

Fig. 52: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (2 of 3) Heated Oxygen Sensor (HO2S) Heater D15Z1 Federal Model

Fig. 53: Honda Civic EX 1994 - Component Locations - Code 41 Flow Chart (3 of 3) Heated Oxygen Sensor (HO2S) Heater D15Z1 Federal Model

Honda Civic EX 1994 - CODE 43 - HEATED OXYGEN SENSOR (HO2S) CIRCUIT OR FUEL SUPPLY SYSTEM ALL MODELS EXCEPT D15B8 CALIF. MODEL

Fig. 54: Honda Civic EX 1994 - Component Locations - Code 43 Flow Chart (1 of 2) (HO2S) Circuit Or Fuel Supply System All Models Except D15B8

Fig. 55: Honda Civic EX 1994 - Component Locations - Code 43 Flow Chart (2 of 2) (HO2S) Circuit Or Fuel Supply System All Models Except D15B8

Honda Civic EX 1994 - CODE 48 - HEATED OXYGEN SENSOR (HO2S) D15Z1 FEDERAL MODEL

Fig. 56: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (1 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Fig. 57: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (2 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Fig. 58: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (3 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Fig. 59: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (4 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Fig. 60: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (5 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Fig. 61: Honda Civic EX 1994 - Component Locations - Code 48 Flow Chart (6 of 6) Heated Oxygen Sensor (HO2S) D15Z1 Federal Model

Honda Civic EX 1994 - 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 for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedure.