Engine Controls - Tests W/codes Acura Integra II

INTRODUCTION

If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no fault codes 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.).

CHECK ENGINE LIGHT

All models are equipped with a CHECK ENGINE light. As a bulb check, light will illuminate when ignition is on and engine is not running. CHECK ENGINE light will also illuminate when a system failure is detected and a corresponding trouble code will set in Electronic Control Unit (ECU) memory.

Hard Failures

Hard failures cause malfunction light 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 using diagnostic (code) charts. 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.

Intermittent Failures

Intermittent failures may cause CHECK ENGINE light to flicker or illuminate and go out after the intermittent fault goes away. However, the corresponding trouble code will be retained in ECU memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from ECU 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.

RETRIEVING CODES

Locate ECU under carpet on passenger's footwell, and check for trouble codes. Observe red LED on top of ECU. LED indicates a system failure code by number of blinks.

Red LED indicates component problems with a blinking series of codes. Trouble codes 1-9 are indicated by individual short blinks. Codes 10-59 are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add long and short blinks together to determine trouble code.

If codes other than those listed are indicated, substitute a known good ECU, and recheck. If codes do not reappear, replace ECU. CHECK ENGINE light and red LED may come on indicating a system problem due to a poor or intermittent connection. Check all related connections, and repair as necessary. Whenever CHECK ENGINE light comes on and red LED stays on steadily, replace ECU.

Note. Before starting tests, ensure engine is in good mechanical condition and adjusted to specifications.

CLEARING CODES

To reset ECU, remove HAZARD fuse at battery positive terminal for 10 seconds.

SUMMARY

If no hard fault 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 procedures.

TROUBLE CODE IDENTIFICATION (1)

CODE 0, NO CODES

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

Scheme 8

1. Turn ignition on. If oil pressure light is on, go to next step. If light is off, inspect fuse No. 23. If fuse No. 23 is okay, repair open circuit in Yellow wire between fuse and combination meter.
2. If oil pressure light is on, turn ignition off. Connect ECU test harness connector between ECU and ECU connector. Jumper ECU terminal B6 to ground. (Scheme 8) Turn ignition on. If CHECK ENGINE light is now on, go to next step. If light is off, replace CHECK ENGINE light bulb or repair open in Green/Orange wire between ECU terminal B6 and combination meter.
3. Measure voltage individually between ground and ECU terminals A2, A4, A16 and A18. If less than one volt is present on all terminals, substitute a known good ECU. If problem goes away, replace ECU. If problem does not go away, repair open in wire between ECU and any terminals reading more than one volt.

CHECK ENGINE LIGHT ON, LED DOES NOT FLASH

1. Attempt to start engine. Verify CHECK ENGINE light comes on and goes off 2 seconds after ignition is turned on. If CHECK ENGINE light goes off, system is okay at this time. Test drive may be necessary.
2. Check for loose wires and poor connections at thermostat housing, main relay connector, ECU fuse and fuse No. 24 (main fuse box). If CHECK ENGINE light stays on, check LED for trouble codes. If any trouble codes are present, see appropriate TROUBLE CODES diagnostic procedures.
3. If no codes are present, verify if engine will start. If engine will start, turn ignition off. Disconnect connector "B" of ECU. (Scheme 8) Turn ignition on and check to see if CHECK ENGINE light is on. If light is on, repair short to ground in Yellow/Red wire between ECU terminal B6 and CHECK ENGINE light.
4. If CHECK ENGINE light is not on, substitute a known good ECU, and recheck. If problem is corrected, replace ECU. If engine will not start, remove and inspect 10 amp ECU fuse and fuse No. 24. Replace as necessary. If fuse is okay, turn ignition on.
5. Individually disconnect connector from MAP, throttle angle and EGR lift sensors. If CHECK ENGINE light shuts off properly, replace sensor causing light to go out. If light remains on, turn ignition off. Connect ECU test harness, but disconnect connector "C" from ECU. Check for continuity between ground and terminals C13 and C15 of ECU connector.
6. If continuity exists, repair short to ground in Yellow/White wire between C13 and throttle angle or EGR lift sensors. Repair short to ground in Red/Yellow wire between C15 and MAP sensor. If continuity does not exist, reconnect all connectors. Turn ignition on.
7. Individually connect terminals A16 and A18 of ECU connector "A" to ground. Check to see if CHECK ENGINE light is on or off after 2 seconds of turning ignition on. If light turns off, repair open in Brown/Black wire between A16 and ground at thermostat housing.
8. If light is still on, measure voltage between A13, A15 and A18 (negative) of ECU test connector. If battery voltage is not present, repair open in Yellow/Black wire between A13, A15 and main relay. Check main relay and wiring connectors at main relay. If battery voltage is present, substitute a known good ECU, and recheck. If system operates properly, replace ECU.

CODE 1: O2 SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start and warm engine to normal operating temperature. Check fuel pressure. See «BASIC TESTING»(/acura/integra/ii-1989-1993/remont/testing-diagnostics/#engine-controls-basic-testing) article in the ENGINE PERFORMANCE Section. Repair fuel system if not within specification.
2. Road test vehicle. With transmission in second gear, accelerate at wide open throttle for at least 5 seconds, and then decelerate with throttle fully closed for at least 5 seconds. Check if CHECK ENGINE light is on and if LED is indicating Code 1.
3. If light is not on, problem is intermittent. Check for poor connections at O2 sensor, ECU and round connector No. C216 at right shock tower.
4. If light is on, disconnect O2 sensor connector. Attach voltmeter to vehicle ground and O2 sensor connector.
5. With engine at normal operating temperature, momentarily open throttle wide open, and then close throttle. Voltage at wide open throttle should be greater than .6 volt and less than .4 volt at fully closed throttle.
6. If voltage is not within specification, replace O2 sensor. If voltage is within specification, perform diagnostic procedure for Code 43.

CODE 3: MAP SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE light. If light is off, problem is intermittent. Check for poor or loose connections at MAP sensor and ECU. Test drive, and check again.
2. If light is on and Code 3 is present, turn ignition off. Disconnect 3-wire MAP sensor connector. Turn ignition on. Measure voltage between MAP sensor Yellow/Red (positive) wire and ground. If reading is not about 5 volts, repair open in Yellow/Red wire between ECU terminal C15 and MAP sensor.
3. If wire is okay, substitute a known good ECU. If problem goes away, replace ECU. If voltage is about 5 volts, measure voltage between Yellow/Red (positive) and Green/White (negative) wires. If about 5 volts are not present, repair open in Green/White wire between ECU terminal C14 and MAP sensor.
4. If wire is okay, substitute a known good ECU, and recheck. If voltage is now okay, replace ECU. With voltage present between Yellow/Red and Green/White wires, measure voltage between White (positive) and Green/White (negative) wires.
5. If voltage reading is not about 5 volts, repair open or short in White wire between ECU terminal C11 and MAP sensor. If wire is okay, substitute a known good ECU, and recheck. If voltage is about 5 volts, turn ignition off. Reconnect MAP sensor connector.
6. Connect ECU test harness between ECU and harness. Turn ignition on. Measure voltage between terminals C11 and C14 of ECU connector "C". If voltage is about 3 volts, substitute a known good ECU. If system functions properly, replace ECU. If about 3 volts are not present, replace MAP sensor.

CODE 4: CRANK SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

Scheme 9

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and ECU LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at distributor connector and connector C216 at right shock tower. Test drive, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 4, turn ignition off. Disconnect 8-pin connector from TDC/CYL/CRANK sensor connector at distributor. Measure resistance between terminals "C" and "D". (Scheme 9) If resistance is not 350-700 ohms, replace distributor assembly. If resistance is within specification, check for continuity between ground and terminals "C" and "D". If continuity exists, sensor is shorted to ground. Replace distributor assembly.
3. If continuity does not exist, reconnect 8-pin connector. Connect ECU test harness to ECU main harness side only. Measure resistance between harness terminals B10 and B12. (Scheme 8) If resistance is not 350-700 ohms, repair Orange and/or White wires between ECU and 8-pin connector.
4. If resistance is within specification, check for continuity to ground on terminal B10. If continuity exists, repair short in Orange wire between B10 and distributor connector. If continuity does not exist, substitute a known good ECU. If condition goes away, replace ECU.

CODE 5: MAP SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and ECU LED lights. If lights are off, problem is intermittent. Check all electrical connections and vacuum hoses. Test drive, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 5, turn ignition off. Connect hand-held vacuum pump to MAP sensor hose at throttle body. Apply vacuum. If vacuum holds, go to next step. If vacuum does not hold, attach vacuum pump to MAP sensor. Apply vacuum. If vacuum does not hold, replace MAP sensor. If vacuum holds, check MAP sensor vacuum hose for cracks, splits and looseness. Repair as necessary.
3. Check vacuum supply to MAP sensor connection on throttle body with engine running. If vacuum is not present, remove restriction or replace throttle body. If vacuum supply is okay, turn ignition off. Connect ECU test harness between ECU and ECU connector. Turn ignition on. Measure voltage between ECU terminals C11 (positive) and C14 (negative). (Scheme 8)
4. If voltage is not about 3 volts, replace MAP sensor. If voltage reading is about 3 volts, start engine, and allow it to idle. Recheck voltage between C11 and C14. If voltage is about 1 volt, substitute a known good ECU. If condition goes away, replace ECU. If voltage is not 1 volt at idle, replace MAP sensor.

CODE 6: COOLANT (TW) SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

Scheme 10

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at TW sensor and connectors C216 and C318 at right shock tower. Test drive, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 6, start and run engine until cooling fan comes on. Turn engine off. Measure resistance between sensor Red/White and Green wire terminals. (Scheme 10) If resistance value is not 200-400 ohms, replace coolant sensor.
3. If resistance value is within specification, turn ignition on. Measure voltage between Red/White (positive) terminal on sensor harness and ground. If about 5 volts are present, go to step 6). If voltage is not about 5 volts on A/T models, disconnect 18-pin connector from A/T control unit.
4. Recheck voltage at Red/White (positive) wire terminal. If voltage is about 5 volts, replace A/T control unit. On all models, if about 5 volts are not present, repair open or short in Red/White wire between ECU terminal C6, A/T control unit and TW sensor.
5. If wire is okay, substitute a known good ECU, and recheck. If condition goes away or specified voltage is now available, replace ECU.
6. If voltage is about 5 volts from step 3), measure voltage between Red/White (positive) and Green (negative) wire terminals.
7. If about 5 volts are not present, repair open in Green wire between ECU connector C12 and TW sensor. If about 5 volts are present, substitute a known good ECU. If system operates properly, replace ECU.

CODE 7: THROTTLE ANGLE SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine. Verify if CHECK ENGINE and LED lights are on and if LED indicates Code 7. If light indicates Code 7, go to next step. If light does not indicate Code 7, problem is intermittent. Check for poor or loose connections at throttle angle sensor, connector C216 at right shock tower and connector C318 at left shock tower. Test drive, and check again.
2. If light is on, turn ignition off. Disconnect 3-wire connector from throttle angle sensor. Turn ignition on. Measure voltage between Yellow/White (positive) and Green (negative) wire terminals. If about 5 volts are not present, go to step 5). If voltage is about 5 volts, turn ignition off. Reconnect sensor connector. Connect ECU test harness between ECU and ECU connector.
3. Turn ignition on. Measure voltage between ECU terminals C7 (positive) and C12 (negative). (Scheme 8) Voltage should read.3 volt at closed throttle and about 4.5 volts at wide open throttle. Transition between lower and upper voltage specifications as throttle is depressed should be smooth.
4. On A/T models, if sensor voltages are not correct, disconnect 18-pin connector from A/T control unit. Recheck voltages. If voltages are correct, replace A/T control unit. On all models, if voltages are not correct, replace throttle angle sensor or repair open or short in Red/Blue wire between ECU terminal C7, A/T control unit (if equipped) and throttle sensor.
5. If voltage reading between Yellow/White (positive) and Green (negative) wire terminals in step 2) was not about 5 volts, measure voltage between Yellow/White (positive) wire terminal and ground.
6. If about 5 volts are present, repair open in Green wire between ECU terminal C12 and throttle angle sensor. If about 5 volts are not present, turn ignition off. Connect ECU test harness between ECU and ECU connector. Turn ignition on.
7. Measure voltage between ECU terminals C13 (positive) and C12 (negative). If about 5 volts are present, repair open in Yellow/White wire terminal between ECU terminal C13 and throttle angle sensor. If about 5 volts are not present, substitute a known good ECU. If condition goes away, replace ECU.

CODE 8: TDC SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at distributor (round) connector C216 at right shock tower. Test drive vehicle, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 8, turn ignition off. Disconnect 8-pin sensor connector at distributor. Measure resistance between White/Blue ("A") and Orange/Blue ("B") terminals. (Scheme 9) If resistance is not 350-700 ohms, replace distributor assembly.
3. If resistance is within specification, individually check for continuity between ground and White/Blue wire and then Orange/Blue wire. If continuity exists, sensor is shorted to ground. Replace distributor assembly. If continuity does not exist, reconnect connector.
4. Connect ECU test harness to main wiring harness side only. Measure resistance between harness terminals C3 and C4. (Scheme 8) If resistance is not 350-700 ohms, repair open in Orange/Blue and/or White/Blue wire.
5. If resistance is within specification, check for continuity to ground on terminal C3. If continuity does not exist, substitute a known good ECU. If condition goes away, replace original ECU. If continuity exists, repair short in Orange/Blue wire between ECU terminal C3 and distributor connector.

CODE 9: CYL SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at distributor (round) connector C216 at right shock tower. Test drive vehicle, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 9, turn engine off. Disconnect 8-pin sensor connector nearest sensor. Measure resistance between terminals "F" and "G". (Scheme 9) If reading is not 350-700 ohms, replace distributor assembly. If reading is within specification, go to next step.
3. Check continuity between ground and terminals "F" and "G". If continuity exists, replace distributor assembly. If continuity does not exist, reconnect sensor connector. Attach ECU test harness to main wire harness side only. Using an ohmmeter, check resistance between harness terminals C1 and C2. (Scheme 8)
4. Resistance should be 350-700 ohms. If resistance is not as specified, repair open in Blue/Green and/or Blue/Yellow wires.
5. If resistance is okay, check for continuity to ground on terminal C1. If continuity does not exist, substitute a known good ECU. If condition goes away, replace original ECU. If continuity exists, repair short in Blue/Green wire between ECU terminal C1 and distributor connector.

CODE 10: AIR TEMPERATURE (TA) SENSOR

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at TA sensor and round connector C318 at left shock tower. Test drive vehicle, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 10, turn ignition off. Disconnect 2-pin TA sensor connector. If resistance across sensor terminals is not 1000-4000 ohms, replace TA sensor. If resistance is okay, turn ignition on. Measure voltage between Red/Yellow wire terminal and ground.
3. If voltage is about 5 volts, go to step 4). If voltage is not about 5 volts, repair open or short in Red/Yellow wire between TA sensor and ECU terminal C5. If wire is okay, substitute a known good ECU. If condition goes away, replace ECU.
4. Measure voltage between Red/Yellow (positive) and Green (negative) wire terminals. If voltage is not about 5 volts, repair open in Green wire between ECU terminal C12 and TA sensor. If voltage is about 5 volts, substitute a known good ECU. If condition goes away, replace ECU.

CODE 12: EGR SYSTEM

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for at least 10 seconds to reset ECU. Warm engine until cooling fan comes on. Observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent.
2. Check for poor and loose connections at EGR position sensor, connector C216 at right shock tower, connector C318 at left shock tower, control box and ECU. If CHECK ENGINE light is on and LED indicates Code 12, start engine. Disconnect vacuum hose No. 16 from EGR valve. Connect vacuum gauge to hose.
3. If vacuum is present, disconnect 4-pin connector from control box. If no vacuum is present, go to next step. Check vacuum again on hose No. 16. If vacuum is present, check vacuum hose routing. If routing is okay, replace EGR control solenoid valve. If vacuum is not present, check for short or ground in Red wire between EGR control solenoid valve and ECU terminal A8. If wire is okay, substitute a known good ECU. If system operates properly, replace original ECU.
4. If vacuum is not present during first vacuum test in step 3), install vacuum pump on EGR valve. With engine idling, apply 8 in. Hg to EGR valve. If engine does not stall and EGR valve does not hold vacuum, replace EGR valve.
5. If engine stalls and EGR valve holds vacuum, disconnect 4-pin connector from control box. Measure voltage between Black/Yellow wire terminal and ground. If battery voltage is not present, repair open in Black/Yellow wire between solenoid valve and fuse No. 24.
6. If battery voltage is present, reconnect vacuum gauge to vacuum hose No. 16. With engine running, connect terminal "B" of 4-pin connector of control box to battery positive terminal. While observing vacuum gauge, connect terminal "D" to negative battery terminal.
7. If gauge does not read 8 in. Hg within one minute, turn ignition off. Inspect hoses No. 16 and 20 for leaks, restrictions and misrouting. If problem is found, repair as necessary. If hoses are okay, disconnect lower hose on EGR control solenoid valve, and connect a vacuum gauge.
8. Start engine, and allow to idle. If 6-10 in. Hg is not present, replace Constant Vacuum Control (CVC) valve. If 6-10 in. Hg is present, replace EGR control solenoid valve. If gauge reads 8 in. Hg from previous step, reconnect 4-pin connector, and ensure ignition is off.
9. Connect Test Harness (07GMJ-ML80100 ) to EGR lift sensor harness. Turn ignition on. Measure voltage between Red (positive) and Green (negative) wire terminals. If about 5 volts are not present, repair open in Yellow/White wire in connector C216 or Green wire in connector C318 between EGR valve and ECU terminal C13.
10. If 5 volts are present, measure voltage between White (positive) and Green (negative) wire terminals. If about 1.2 volts are not present, replace EGR valve. Repair short in Yellow wire between terminal C8 and EGR lift sensor. If wire is okay, substitute a known good ECU. If proper voltage is present, replace ECU.
11. If 1.2 volts are present, observe voltmeter, and apply 8 in. Hg to EGR valve. Repeat several times, fully releasing vacuum between checks. If maximum voltage is not 4 volts, replace EGR valve. If maximum voltage is 4 volts, ensure voltage consistently increases and decreases as vacuum increases and decreases.
12. If voltage does not increase and decrease with vacuum, replace EGR valve. If vacuum increases and decreases with vacuum, reconnect hose No. 16 to EGR valve. Turn ignition off. Connect ECU test harness to ECU. Start engine, and allow to idle. Measure voltage between ECU terminals C8 (positive) and C12 (negative). If about 1.2 volts are not present, repair open in Green/Red wire between ECU terminal C8 and EGR lift sensor.
13. If 1.2 volts are present, connect jumper between A8 and A18. If engine does not stall, repair open in Red wire between A8 and EGR control solenoid valve. If engine stalls, substitute a known good ECU. If condition goes away, replace ECU.

CODE 13: ATMOSPHERIC (PA) SENSOR

1. Turn ignition off. Remove HAZARD fuse at battery positive terminal for 10 seconds to reset ECU. Turn ignition on. Verify if CHECK ENGINE and LED lights are on. If lights are not on, problem is intermittent. Test drive, and retest.
2. If CHECK ENGINE light is on and LED indicates Code 13, turn ignition off. Connect ECU test harness to main harness, not ECU. On A/T models, disconnect 18-pin connector from A/T control unit. Check continuity between C9 and ground.
3. If continuity exists, repair short in Red/White wire between ECU terminal C9 and A/T control unit. If no continuity is present, substitute a known good A/T control unit, and recheck. If Code 13 is not indicated, replace A/T control unit.
4. If Code 13 is still present, turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Substitute a known good ECU. Turn ignition on. If CHECK ENGINE light is on and Code 13 is present, replace ECU (PA sensor is built into ECU).

CODE 14: ELECTRONIC AIR CONTROL VALVE (EACV)

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at EACV, C317 and C318. Test drive, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 14, turn ignition off. Measure resistance between EACV terminals. If resistance is not 8-15 ohms, replace EACV. If resistance is okay, check continuity to ground between each EACV terminal.
3. If continuity exists, replace EACV. If continuity does not exist, turn ignition on. Measure voltage between Black/Yellow and Blue/Yellow wire terminals. If battery voltage is present, go to next step. If battery voltage is not present, go to step 5).
4. Disconnect ECU connector "A". If battery voltage is now present, repair short in Blue/Yellow wire between ECU terminal A11 and EACV. If battery voltage is not present, substitute a known good ECU, and recheck. If condition goes away, replace ECU.
5. Measure voltage between Black/Yellow EACV wire terminal and ground. If battery voltage is present, go to step 6). If battery voltage is not present, repair open in Black/Yellow wire between EACV and fuse No. 24.
6. Turn ignition off. Reconnect 2-pin EACV connector. Connect ECU test harness connector "A" to ECU main harness side only. Turn ignition on. Measure voltage between harness terminals A11 (positive) and A2 (negative). (Scheme 8) If battery voltage is present, go to next step. If battery voltage is not present, repair open in Blue/Yellow wire between harness terminal A11 and EACV.
7. Connect and disconnect harness terminals A11 and A2. Listen for clicking from EACV. If clicking is not heard, replace EACV. If clicking is heard, go to next step.
8. Substitute a known good EACV, and recheck EACV. If okay, substitute a known good ECU, and recheck. If condition goes away, replace ECU.

CODE 15: IGNITION OUTPUT SIGNAL

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Start engine, and observe CHECK ENGINE and LED lights. If lights are off, problem is intermittent. Check for poor and loose connections at distributor connector, ECU and round connector C216 at right shock tower. Test drive, and check again.
2. If CHECK ENGINE light is on and LED indicates Code 15, turn ignition off. Disconnect 2-pin connector at distributor. Turn ignition on. Measure voltage between ground and Black/Yellow wire terminal on wiring harness side. If battery voltage is not present, repair open Black/Yellow wire between 2-pin connector and ignition switch.
3. If battery voltage is present, turn ignition off. Reconnect 2-pin distributor connector. Connect ECU test harness between ECU and ECU connector. Turn ignition on.
4. Individually measure voltage between ECU terminals B15 (positive) and B17 (positive) and A18 (ground). (Scheme 8) If about 10 volts are not present, repair open or short in White wire between distributor and ECU terminals B15 and B17 or replace ignitor unit. If about 10 volts are present at any terminal, substitute a known good ECU, and recheck. If condition goes away, replace ECU.

CODE 16: FUEL INJECTOR CIRCUIT

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Try to start engine. If engine starts, go to next step. If engine does not start, go to step 5).
2. If engine starts, verify if CHECK ENGINE and LED lights are on. If lights are not on, problem is intermittent. Check for poor and loose connections at injectors, injector resistor and round connector C318 at left shock tower. Test drive, and check again.
3. If CHECK ENGINE light is on and LED indicates Code 16, check for clicking sound of each injector using a stethoscope with engine at idle. If injectors are clicking, substitute a known good ECU, and recheck. If problem goes away, replace original ECU.
4. If injector(s) does not click, turn ignition off. Disconnect 2-pin injector connector from affected injector. Measure resistance between injector terminals. Resistance should be 1.5-2.5 ohms. If resistance is not 1.5-2.5 ohms, replace injector. If resistance is okay, go to step 6).
5. If engine does not start, turn ignition off. Disconnect injector terminals. Check resistance of all injectors. If resistance value is not 1.5-2.5 ohms, replace injector(s).
6. If resistance values are within specification, turn ignition on. Measure voltage between Red/Black wire of injector terminal and ground. If battery voltage is not present, go to step 8). If battery voltage is present, reconnect 2-pin injector connectors. Turn ignition off.
7. Connect ECU test harness to ECU. (Scheme 8) Turn ignition on. Check voltage at following terminals. Injector No. 1 - A1 Red/Black (pos.) and Brown (neg.). Injector No. 2 - A3 Red/Black (pos.) and Red (neg.). Injector No. 3 - A5 Red/Black (pos.) and Light Blue (neg.). Injector No. 4 - A7 Red/Black (pos.) and Yellow (neg.). If battery voltage is not present, repair open in wire between injector and A1, A3, A5 and A7. If battery voltage is present, substitute a known good ECU, and retest. If specified voltage is now present, replace ECU.
8. Turn ignition off. Disconnect 6-pin connector at injector resistor. Turn ignition on. Measure voltage between Yellow/Black wire terminal and ground. If battery voltage is not present, repair open in Yellow/Black wire between injector resistor and main relay.
9. If battery voltage is present, replace injector resistor. If still no voltage is present, repair open in Red/Black wire between 2-pin connector and resistor.

CODE 17: VEHICLE SPEED SENSOR (VSS)

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Road test vehicle. With transmission in 2nd gear, accelerate to 3500 RPM and decelerate to 1500 RPM with throttle fully closed. Verify if CHECK ENGINE light comes on and if LED indicates Code 17. If LED does not indicate Code 17, problem is intermittent. Check for poor connections and loose wires at VSS connector.
2. If lights are on, block rear wheels, and set parking brake. Raise front of vehicle, and support with safety stands. Connect ECU test harness between ECU and ECU connector.
3. Turn ignition on. Slowly rotate left front wheel and measure voltage between ECU terminals B16 (positive) and A18 (negative). (Scheme 8) If voltage does not pulse between 0-5 volts, check for open or short in Yellow/Red wire between ECU terminal B16 (positive) and VSS. If wire is okay, replace VSS. If VSS is okay, replace ECU.
4. If voltage pulses between 0 and 5 volts, substitute a known good ECU, and recheck. If condition goes away, replace ECU.

CODE 43: FUEL SUPPLY SYSTEM

Note. For wiring diagrams, see WIRING DIAGRAMS article in the ENGINE PERFORMANCE Section. For vacuum diagrams, see VACUUM DIAGRAMS article in the ENGINE PERFORMANCE Section.

1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Start engine, and allow cooling fan to come on. Hold engine at 3000 RPM for 2 minutes. Observe CHECK ENGINE and LED lights. If lights are not on, problem is intermittent.
2. Check for poor and loose connections at O2 sensor and round connector C216 at right shock tower. If CHECK ENGINE light is on and LED indicates Code 43, inspect fuel pressure regulator. See «BASIC TESTING»(/acura/integra/ii-1989-1993/remont/testing-diagnostics/#engine-controls-basic-testing) article in the ENGINE PERFORMANCE Section. If driveability problems are also present, test fuel related components. See «SYSTEM/COMPONENT TESTS»(/acura/integra/ii-1989-1993/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) article in the ENGINE PERFORMANCE Section. Repair as necessary.
3. If fuel regulator is okay, disconnect O2 sensor. With engine running, measure voltage between O2 sensor and ground. Voltage should be above .6 volt at wide open throttle up to 4500 RPM. When throttle is quickly released, voltage should be .4 volt.
4. If voltage is not correct, replace O2 sensor. If voltage is correct, stop engine. Reconnect O2 sensor connector. Connect ECU test harness to ECU. Restart engine, and warm to normal operating temperature. Measure voltage between C16 and A18.
5. Voltage should be as in step 3). If voltage is not correct, repair open or short in White wire between C16 and O2 sensor. If voltage is correct, substitute a known good ECU, and recheck. If problem goes away, replace ECU.

See also:
• BASIC TESTING
• TESTS W/O CODES
• WIRING DIAGRAMS
• SYSTEM/COMPONENT TESTS
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