Engine Controls - System & Component Testing: Other Isuzu Oasis I

AIR INTAKE SYSTEM

Intake Air Control System (Prelude)

Intake air control solenoid valve is located at right side of engine, under intake air duct. When engine speed is below 3970 RPM, the ECM supplies ground to the Intake Control Solenoid. This opens the solenoid valve sending intake manifold vacuum to the Intake Control Diaphragm.

Scheme 37

1. Start engine and allow to idle. Disconnect No. 8 vacuum hose from upper port on intake control solenoid valve. See «VACUUM DIAGRAMS»(ref-16356) article. Check for vacuum at solenoid valve. If vacuum does not exist, go to next step. If vacuum exists, go to step 6).
2. Disconnect No. 8 vacuum hose from intake control vacuum tank. See «VACUUM DIAGRAMS»(ref-16356) article. Check for vacuum at intake control vacuum tank. If vacuum exists, go to next step. If vacuum does not exist, repair blockage or vacuum leak between intake control vacuum tank and intake manifold.
3. Turn ignition off. Disconnect intake control solenoid valve 2-pin connector. Turn ignition on. Measure voltage between intake control solenoid valve connector terminals No. 1 (White wire) and No. 2 (Black/Yellow wire). See WIRING DIAGRAMS article. If battery voltage is not present, go to next step. If battery voltage is present, replace intake control solenoid valve.
4. Measure voltage between ground and intake control solenoid valve 2-pin connector terminal No. 2 (Black/Yellow wire). If battery voltage is present, go to next step. If battery voltage is not present, repair open in Black/Yellow wire between intake control solenoid valve connector and fuse No. 14 (ECU CRUISE CONTROL) located in under-dash fuse/relay box. See WIRING DIAGRAMS article.
5. Turn ignition off. Reconnect intake control solenoid valve 2-pin connector. Turn ignition on. Connect a fused jumper wire between PCM 32-pin connector "A" terminal A9 (Brown/Black wire) and terminal A25 (White wire). (Scheme 37) If intake control solenoid valve does not click when jumper wire is connected, repair open in White wire between intake control solenoid valve and PCM. See WIRING DIAGRAMS article. If intake control solenoid valve clicks when jumper wire is connected, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
6. Increase engine speed to more than 4200 RPM. Check for vacuum at solenoid valve upper port. See «VACUUM DIAGRAMS»(ref-16356) article. If vacuum does not exist, go to step 8). If vacuum exists, disconnect intake control solenoid valve 2-pin connector. Check for vacuum again. If vacuum does not exist, go to next step. If vacuum exists, replace intake control solenoid valve.
7. Turn ignition off. Disconnect PCM 32-pin connector "A". (Scheme 37) Check for continuity between ground and intake control solenoid valve 2-pin connector terminal No. 1 (White wire). If continuity exists, repair short in White wire between PCM and intake control solenoid valve. See WIRING DIAGRAMS article. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.
8. Apply vacuum to No. 8 vacuum hose disconnected from intake control solenoid valve upper port. See «VACUUM DIAGRAMS»(ref-16356) article. If vacuum hose holds a vacuum, intake system is okay at this time. If vacuum hose does not hold a vacuum, check vacuum hoses for proper connections, disconnected hose and/or cracked or leaking hoses. If vacuum hoses are okay, replace intake control diaphragm.

Intake Air By-Pass (IAB) Control System

The IAB control solenoid valve is located at lower rear of engine. IAB control solenoid valve is off when engine speed is more than 4900 RPM.

Ground Circuits

1. Measure resistance to ground at appropriate PCM ground terminals. See «POWER & GROUND CIRCUIT TERMINAL IDENTIFICATION»(ref-16351-S23057840032000122900000). (Scheme 37) Resistance should be zero ohms for each circuit. If resistance is not zero ohms, repair open to ground.
2. To check voltage drop on ground circuit, connect negative lead of DVOM to a good ground. Connect positive lead to each ground terminal. With engine running, voltmeter should indicate less than 0.1 volt. If voltage is more than 0.1 volt, check for open, corrosion, or loose connection on ground lead. See WIRING DIAGRAMS article.

Power Circuits

1. Check for battery voltage between appropriate PCM connector Voltage Back-Up (VBU) terminal and ground. See «POWER & GROUND CIRCUIT TERMINAL IDENTIFICATION»(ref-16351-S23057840032000122900000). (Scheme 37) If battery voltage does not exist, check appropriate PCM fuse. See «PCM POWER CIRCUIT FUSE IDENTIFICATION»(ref-16351-S31390592262000122900000). If fuse is okay, check for an open in wire between fuse and appropriate PCM connector terminal. See WIRING DIAGRAMS article.
2. Turn ignition on. Check for battery voltage between appropriate PCM connector Ignition Power (IGP) source terminal and ground. See «POWER & GROUND CIRCUIT TERMINAL IDENTIFICATION»(ref-16351-S23057840032000122900000). If battery voltage does not exist, check appropriate fuse. See «PCM POWER CIRCUIT FUSE IDENTIFICATION»(ref-16351-S31390592262000122900000). If fuse is okay, check for open in wire between fuse and appropriate PCM connector terminal. Check for defective ignition switch. See WIRING DIAGRAMS article.

POWER & GROUND CIRCUIT TERMINAL IDENTIFICATION

PCM POWER CIRCUIT FUSE IDENTIFICATION

RELAYS

Note. If engine starts and continues to run, PGM-FI main relay is okay.

Scheme 38

1. On Civic, PGM-FI main relay is located under right side of instrument panel. On all others, PGM-FI main relay is located under left side of instrument panel, near steering column.
2. Remove PGM-FI main relay. Using a fused jumper wire, connect battery voltage to PGM-FI main relay terminal No. 2. Using another jumper wire, connect battery ground to relay terminal No. 1. (Scheme 38) Check for continuity between relay terminals No. 4 and No. 5. If continuity exists, go to next step. If continuity does not exist, replace PGM-FI main relay and re-test.
3. Move battery voltage to PGM-FI main relay terminal No. 5. Move battery ground to relay terminal No. 3. Check for continuity between relay terminals No. 6 and No. 7. If continuity exists, go to next step. If continuity does not exist, replace PGM-FI main relay and re-test.
4. Move battery voltage to PGM-FI main relay terminal No. 6. Move battery ground to relay terminal No. 1. Check for continuity between relay terminals No. 4 and No. 5. If continuity does not exist, replace relay and re-test. If continuity exists, relay is okay. If fuel pump does not operate after checking relay go to «PGM-FI MAIN RELAY HARNESS CHECK»(ref-16351-S11346284312000122900000).

Scheme 39

1. Turn ignition off. Disconnect PGM-FI main relay 7-pin harness connector. Check for continuity between ground and main relay connector terminal No. 3. (Scheme 39) If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between main relay connector terminal No. 3 and ground connection. See WIRING DIAGRAMS article.
2. Ensure ignition switch is off. Measure voltage between ground and main relay connector terminal No. 7. See WIRING DIAGRAMS article. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between fuse and main relay or replace fuse in fuse/relay box. See WIRING DIAGRAMS article. See «PCM POWER CIRCUIT FUSE IDENTIFICATION»(ref-16351-S31390592262000122900000).
3. Turn ignition on. Measure voltage between ground and main relay connector terminal No. 5. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between fuse and main relay or replace fuse in fuse/relay box. See WIRING DIAGRAMS article. See «PCM POWER CIRCUIT FUSE IDENTIFICATION»(ref-16351-S31390592262000122900000).
4. Put transmission in Park or Neutral (A/T) or depress clutch pedal (M/T). Turn ignition switch to START position. Measure voltmeter between ground and main relay connector terminal No. 2. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between START SIGNAL fuse and main relay connector terminal No. 2 or replace fuse in fuse/relay box. See WIRING DIAGRAMS article.
5. Turn ignition off. Disconnect PCM 32-pin connector "A". (Scheme 37) Check for continuity between PGM-FI main relay connector terminal No. 1 and PCM connector "A" terminal A15 (Accord, Oasis & Odyssey) or A16 (Civic, CR-V, & Prelude). See WIRING DIAGRAMS article. If continuity exists, go to next step. If continuity does not exist, repair open in wire between main relay connector terminal No. 1 and PCM connector. See WIRING DIAGRAMS article.
6. Reconnect PCM and PGM-FI main relay connectors. Turn ignition on. Measure voltage between PCM connector terminals B1 and B20 and between B9 and B20 (Accord, Oasis & Odyssey). Measure voltage between PCM connector terminals A10 and A11 and between A10 and A24 (Civic, CR-V & Prelude). On all models, if battery voltage exists, go to next step. If battery voltage does not exist, repair open in suspect wire between PCM connector terminal B1 or B9 and main relay (Accord, Oasis & Odyssey) or terminal A11 or A24 and main relay (Civic, CR-V & Prelude). See WIRING DIAGRAMS article. If wires are okay, replace PGM-FI main relay.
7. Turn ignition off. Measure voltage between PCM connector "A" terminals A15 and B2 (Accord, Oasis & Odyssey) or between terminals A10 and terminal A16 (Civic, CR-V & Prelude). Turn ignition on. On all models, If one volt or less exists for 2 seconds after ignition is first turned on, check PGM-FI main relay. See PGM-FI MAIN RELAY TEST. If more than one volt exists, substitute a known-good PCM and recheck. If one volt or less now exists, replace original PCM.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING article.

Fuel Injector

Fuel injector resistance information is not available from manufacturer. For fuel injector testing, see appropriate MISFIRE IN ONE CYLINDER DETECTED DTC testing in TESTS W/CODES - INTRODUCTION article.

AIR CONDITIONING SIGNAL

Note. This signal informs the PCM that there is a demand for cooling from the A/C system.

1. Turn ignition off. Disconnect A/C pressure switch (all models) and A/C diode (Civic, Oasis, Odyssey & Prelude). See «A/C SIGNAL COMPONENT LOCATIONS»(ref-16351-S30063515622000122900000). Turn ignition on. Measure voltage between PCM connector terminals A27 and B20 (Accord, Oasis & Odyssey) or terminals A9 and C5 (Civic, CR-V & Prelude). (Scheme 37) If 5 volts exists (battery voltage on CR-V & Prelude), go to next step. If specified voltage does not exist, go to step 4).
2. Turn ignition off. Reconnect A/C pressure switch (all models) and A/C diode (Oasis, Odyssey & Prelude) connectors. Turn ignition on. Using a fused jumper wire, momentarily connect PCM connector terminals A17 and B20 (Accord, Oasis & Odyssey) or terminals A9 and A17 (Civic, CR-V, Oasis & Odyssey), several times. (Scheme 37) If A/C compressor clutch makes a clicking sound, go to next step. If A/C compressor clutch does not make a clicking sound, go to step 5).
3. Start engine. Turn A/C and blower motor switches on. If A/C operates, A/C signal is okay. If A/C does not operate, go to step6. 4)Turn ignition switch off. Disconnect the PCM connector A (Accord, Oasis & Odyssey), C (Civic, CR-V & Prelude). Check for continuity between ground and terminals A27 (Accord, Oasis & Odyssey) or C5 (Civic, CR-V & Prelude). If continuity does not exist then substitute a known-good PCM then recheck for voltage. Repeat step 1). If continuity exists, then repair short in wire between A27 or C5 and A/C pressure switch. If specified voltage now exists, replace original PCM. If specified voltage still does not exist, inspect A/C system. Refer to appropriate A/C - HEATER SYSTEM article in the AIR CONDITIONING & HEAT section.
4. Using a fused jumper wire, momentarily connect under-hood fuse/relay box 16-pin connector terminal No. 11 (Accord) or under-hood fuse/relay box 9-pin connector terminal No. 5 (Civic & CR-V) or A/C clutch relay connector terminal No. 4 (Oasis, Odyssey & Prelude)to ground several times. to ground several times. (Scheme 40)& 6. See «A/C SIGNAL COMPONENT LOCATIONS»(ref-16351-S30063515622000122900000). If A/C compressor clutch makes a clicking sound, repair open in wire between A/C clutch relay and PCM connector terminal A17 (all models). See WIRING DIAGRAMS article. If A/C compressor clutch does not make a clicking sound, inspect A/C system. Refer to appropriate A/C - HEATER SYSTEM article in the AIR CONDITIONING & HEAT section.
5. Turn ignition off. Disconnect PCM connectors "A" and "B" (Accord, Oasis & Odyssey) or "A" and "C" (Civic, CR-V & Prelude). Measure voltage between terminals A27 and B20 (Accord, Oasis & Odyssey) or A9 and C5 (Civic, CR-V & Prelude). If there is less that 1 volt measured, then substitute a known-good PCM then recheck for voltage. If specified voltage now exists, replace original PCM. If specified voltage still does not exist, inspect A/C system. Refer to appropriate A/C - HEATER SYSTEM article in the AIR CONDITIONING & HEAT section.

A/C SIGNAL COMPONENT LOCATIONS

Scheme 40

Scheme 41

ALTERNATOR FR SIGNAL

Note. This signal informs PCM when alternator is charging.

Scheme 42

1. Turn ignition off. Disconnect alternator 4-pin connector (3-pin on Canadian models). Turn ignition on. Measure voltage between PCM connector terminals B20 and C5 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C17 (Civic & Prelude). (Scheme 37) If about 5 volts exists, go to step 3). If about 5 volts does not exist, go to next step.
2. Turn ignition off and disconnect negative battery cable. Disconnect PCM connector "C" on all models. Check for continuity between ground and PCM connector terminal C5 (Accord, CR-V, Oasis & Odyssey) or terminal C17 (Civic & Prelude). If continuity exists, repair short in wire between PCM connector and alternator connector. If continuity does not exist, substitute known-good PCM and recheck for about 5 volts. If about 5 volts now exists, replace original PCM.
3. Turn ignition off and reconnect alternator connector. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral, until radiator fan comes on. Allow engine to idle. Measure voltage between PCM connector terminals B20 and C5 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C17 (Civic & Prelude). If voltage does not decrease when headlights and rear defogger is turned on, go to next step. If voltage decreases when headlights and rear defogger is turned on, alternator FR signal is okay.
4. Turn ignition off. Disconnect negative battery cable. Disconnect PCM connector "C" on all models. (Scheme 37) Disconnect alternator 4-pin (3-pin on Canadian models) connector. On all models, connect a jumper wire between ground and alternator harness connector No. 4 terminal. (Scheme 42) Check for continuity between ground and PCM connector terminal C5 (Accord, CR-V, Oasis & Odyssey) or C17 (Civic & Prelude). If continuity exists, problem is within alternator or regulator. If continuity does not exist, repair open in wire between PCM connector and alternator harness connector.

A/T GEAR POSITION SIGNAL

Note. This signal informs the PCM when the transmission is in Park or Neutral.

Note. For A/T gear position signal testing on Accord, CR-V, Oasis & Odyssey, see DTC P1705 or P1706 (ACCORD, CR-V & ODYSSEY): A/T GEAR POSITION SWITCH in TESTS W/CODES - INTRODUCTION article.

Civic D16Y5 CVT & Prelude

1. Turn ignition on. Observe A/T position indicator on instrument panel while selecting each gear position separately. If A/T position indicator functions properly, go to next step. If A/T position indicator does not function properly, see appropriate INSTRUMENT PANEL article in ACCESSORIES/SAFETY EQUIPMENT section.
2. Turn ignition off. Disconnect gauge assembly 16-pin (Prelude) or 14-pin (Civic) connector. Disconnect Transmission Control Module (TCM) 26-pin connector "A". On Prelude, TCM is located in passenger side footwell, next to PCM. On Civic, TCM is located behind passenger side kick panel. On all models, turn ignition on. Measure voltage between PCM connector terminals A9 and C29. (Scheme 37) If about 5 volts does not exist, go to next step. If about 5 volts exists, go to step 4).
3. Turn ignition off. Disconnect PCM 31-pin connector "C". Check for continuity between ground and PCM connector terminal C29. If continuity exists, repair short in wire between PCM connector terminal C29 and gauge assembly. See WIRING DIAGRAMS article. If continuity does not exist, substitute known-good PCM and recheck. If about 5 volts now exists, replace original PCM.
4. Turn ignition off. Reconnect gauge assembly and TCM connectors. Place transmission in Park or Neutral position. Start engine. Measure voltage between PCM connector terminals A9 and C29. If less than one volt exists, go to next step. If less than one volt does not exist, repair open in wire between gauge assembly and PCM connector C29 or between gauge assembly and A/T gear position switch.
5. Measure voltage between PCM connector terminal A9 and terminal C29 with transmission in any gear position except Park or Neutral. If battery voltage exists (Civic), if 5 volts or more exists (Prelude), A/T gear position signal is okay. If specified voltage does not exist, repair short in wire between PCM connector terminal C29 and gauge assembly. See WIRING DIAGRAMS article.

BRAKE SWITCH SIGNAL

Note. This signal informs PCM when brake pedal is depressed.

1. If brake lights are on without depressing brake pedal, check brake light switch and repair or replace as necessary. If brake lights are not on, depress brake pedal. If brake lights come on, go to next step. If brake lights do not come on, check power feed circuit (including fuse) between brake light switch and fuse box. See WIRING DIAGRAMS article. Repair as necessary.
2. Measure voltage between PCM connector terminals A32 and B20 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and D5 (Civic & Prelude). (Scheme 37) If battery voltage exists, brake switch signal is okay. If battery voltage does not exist, repair open in wire between PCM connector terminal B20 (Accord, CR-V, Oasis & Odyssey) or terminal D5 (Civic & Prelude) and brake light switch. See WIRING DIAGRAMS article.

CLUTCH SWITCH SIGNAL

Note. This signal informs PCM when clutch is engaged.

Civic D16Y5 M/T

1. Turn ignition on. Measure voltage between PCM connector terminal A9 and terminal C29. (Scheme 38) If about 5 volts exists, go to step 3). If about 5 volts does exist, go to next step.
2. Depress clutch pedal. Measure voltage between PCM connector terminal A9 and terminal C29. If less than one volt exists, clutch switch signal is okay. If about one volt does not exist, go to step 5).
3. Turn ignition off. Disconnect clutch switch 2-pin connector. Turn ignition on. Measure voltage between PCM connector terminals A9 and C29. If about 5 volts exists, replace clutch switch. If about 5 volts does not exist, go to step 5.
4. Turn ignition off. Disconnect PCM 31-pin connector "C". Check for continuity between ground and PCM connector terminal C29. If continuity exists, repair short in wire between PCM connector terminal C29 and clutch switch. If continuity does not exist, substitute known-good PCM and recheck for voltage between PCM connector terminal A9 and terminal C29. If about 5 volts now exists, replace original PCM.
5. Turn ignition off. Disconnect clutch switch 2-pin connector. Depress clutch pedal and check for continuity between clutch switch terminals. If continuity exists, go to next step. If continuity does not exist, adjust or replace clutch switch.
6. Turn ignition on. Depress clutch pedal. Measure voltage between ground and clutch switch harness connector No. 1 (Red wire). If about 5 volts exists, repair open in Black wire between clutch switch harness connector and ground connection. See WIRING DIAGRAMS article. If about 5 volts does not exist, repair open in Red wire between PCM connector terminal C29 and clutch switch. See WIRING DIAGRAMS article.

POWER STEERING PRESSURE SWITCH SIGNAL

Note. This signal informs PCM when power steering load is high.

1. Turn ignition on. Measure voltage between PCM connector terminals A26 and B20 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C16 (Civic & Prelude). (Scheme 37) If voltage is one volt or more, go to step 3). If voltage is less than one volt, go to next step.
2. Start engine. Turn steering wheel slowly to full lock position. Measure voltage between PCM connector terminals A26 and B20 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C16 (Civic & Prelude). If battery voltage is present, Power Steering Pressure (PSP) switch signal is okay. If battery voltage is not present, go to step 4).
3. Turn ignition off. Disconnect PSP switch 2-pin connector. Switch is located on high pressure hose next to steering gear. Connect a fused jumper wire between the two PSP switch harness connector terminals. Turn ignition on. Measure voltage between PCM connector terminals A26 and B20 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C16 (Civic & Prelude). If voltage is one volt or more, repair open in wire between PCM connector terminal B20 (Accord, CR-V, Oasis & Odyssey) or C16 (Civic & Prelude) and PSP switch. If wire is okay, repair Black wire between PSP switch and ground connection. See WIRING DIAGRAMS article. If voltage is less than one volt, replace PSP switch.
4. Turn ignition off. Disconnect PSP switch 2-pin connector. Switch is located on high pressure hose next to steering gear. Turn ignition on. Measure voltage between PCM connector terminals A26 and B20 (Accord, CR-V, Oasis & Odyssey) or terminals A9 and C16 (Civic & Prelude). If battery voltage is present, replace PSP switch. If battery voltage is not present, go to next step.
5. Turn ignition off. Disconnect PCM 32-pin connector A (Accord, CR-V, Oasis & Odyssey) or 31-pin connector "C" (Civic & Prelude). (Scheme 37) Check for continuity between ground and PCM connector terminal A26 (Accord, CR-V, Oasis & Odyssey) or C16 (Civic & Prelude). If continuity exists, repair short in wire between PCM connector terminal A26 (Accord, CR-V, Oasis & Odyssey) or C16 (Civic & Prelude) and PSP switch connector. See WIRING DIAGRAMS article. If continuity does not exist, substitute a known good PCM, then recheck for voltage. If battery voltage now exists, replace original PCM.

STARTER SWITCH SIGNAL

Note. This signal informs PCM when engine is cranking. During this test transmission must be in Neutral or Park position (A/T) or clutch pedal must be depressed (M/T).

1. Place transmission in Neutral or Park position (A/T) or depress clutch pedal (M/T). Turn ignition switch to START position. Measure voltage between PCM connector terminals A26 and B20 (Accord, CR-V, Oasis & Odyssey) or A9 and C6 (Civic & Prelude). (Scheme 37) If battery voltage exists, starter switch signal is okay. If battery voltage does not exist, go to next step.
2. Inspect STARTER SIGNAL fuse located in under-dash fuse/relay box. See «STARTER SWITCH FUSE LOCATION»(ref-16351-S20802712102000122900000). If fuse is okay, repair open in wire between STARTER SIGNAL fuse and PCM connector terminal B20 (Accord, CR-V, Oasis & Odyssey) or C6 (Civic & Prelude). (Scheme 37) If fuse is not okay, repair short in wire between PCM connector terminal B20 (Accord, CR-V, Oasis & Odyssey) or A9 and C6 (Civic & Prelude) and STARTER SIGNAL fuse or between PCM connector terminal B20 (Accord, CR-V, Oasis & Odyssey) or A9 and C6 (Civic & Prelude). and PGM-FI main relay. Replace STARTER SIGNAL fuse. See WIRING DIAGRAMS article.

STARTER SWITCH FUSE LOCATIONS

IDLE AIR CONTROL VALVE

For Idle Air Control (IAC) valve testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

FAST IDLE THERMO VALVE

Note. Fast idle thermo valve is adjusted by manufacturer and should not be disassembled.

CR-V & Prelude

1. Remove intake air duct from throttle body. Ensure engine coolant temperature is less than 86°F (30°C). Start engine and allow to idle. Place finger over lower port in throttle body and check for air flow. If airflow exists, go to next step. If airflow does not exist, replace fast idle thermo valve and re-test.
2. Start engine and run at 3000 RPM with no loads and transmission in Park or Neutral, until radiator fan comes on. Allow engine to idle. Verify fast idle thermo valve is completely closed. If valve is leaking, engine idle speed will decrease when lower port in throttle body is covered. If valve is leaking, check engine coolant level and for air in cooling system. If cooling system is okay, replace fast idle thermo valve and re-test.

IGNITION SYSTEM

Note. For ignition system testing, see BASIC TESTING article.

EXHAUST GAS RECIRCULATION VALVE

For Exhaust Gas Recirculation (EGR) valve testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

Fuel Tank Pressure Sensor

For Exhaust Gas Recirculation (EGR) valve testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

EVAP Control Canister Vent Shut Valve

For EVAP Control Canister Vent Shut Valve testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

EVAP Purge Control Solenoid

For EVAP Purge Control Solenoid testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

EVAP Bypass Solenoid Valve

For EVAP Bypass Solenoid Valve testing see appropriate Diagnostic Trouble Code (DTC) testing in TESTS W/CODES - INTRODUCTION article.

Scheme 43

1. Remove fuel tank filler cap. Disconnect vapor hose from fuel tank side of 2-way valve located on or near fuel tank. Install "T" fitting into hose. Connect vacuum gauge (0-4 in. Hg scale) and hand vacuum pump to "T" fitting. See STEP 1 in (Scheme 43).
2. Apply vacuum slowly and continuously while observing vacuum gauge. Vacuum should stabilize momentarily at 0.2-0.6 in. Hg. If vacuum is as specified, go to next step. If vacuum is not as specified, replace 2-way valve. Re-test system.
3. Move vacuum pump hose from vacuum fitting to pressure fitting. Move vacuum gauge hose from vacuum side to pressure side. See STEP 2 in (Scheme 43). Slowly pressurize vapor line while observing gauge. If pressure momentarily stabilizes at 0.4-1.4 in. Hg, valve is okay. If pressure stabilizes at less than 0.4 in. Hg or more than 1.4 in. Hg, replace valve and re-test.

Scheme 44

1. Remove fuel tank filler cap. Disconnect vapor hose from fuel tank side of 2-way valve, located above EVAP canister. Install "T" fitting into hose. Connect vacuum gauge (0-4 in. Hg scale) and hand vacuum pump to "T" fitting. See STEP 1 in (Scheme 44).
2. Apply vacuum slowly and continuously while observing vacuum gauge. Vacuum should stabilize momentarily at 0.2-0.6 in. Hg. If vacuum is as specified, go to next step. If vacuum is not as specified, replace 2-way valve. Re-test system.
3. Move vacuum pump hose from vacuum fitting to pressure fitting. Move vacuum gauge hose from vacuum side to pressure side. See STEP 2 in (Scheme 44). Slowly pressurize vapor line while observing gauge. If pressure momentarily stabilizes at 0.3 in. Hg, valve is okay. If pressure stabilizes at less than 0.3 in. Hg, replace valve and re-test.

POSITIVE CRANKCASE VENTILATION

Inspect crankcase ventilation hoses and connections for leaks and clogging. Start engine. With engine at idle, pinch and release PCV hose. Valve should click. If valve does not click, check for vacuum at PCV valve end of hose. If manifold vacuum exists, replace PCV valve and recheck. If vacuum does not exist, clear blockage in hose.

Accord A/T

Note. Following procedure should be performed if engine vibrates excessively at idle.

1. Check vacuum lines and hoses for damage and proper connection. Repair/replace hoses as necessary. If vacuum lines and hoses are okay, start and warm engine to normal operating temperature (radiator cooling fan comes on). Allow engine to idle. If idle RPM is less than 800 RPM, go to next step. If idle RPM is not less than 800 RPM, adjust idle speed. See «ON-VEHICLE ADJUSTMENTS»(ref-16352) article.
2. Fully depress brake pedal. With transaxle in gear, have an assistant disconnect and reconnect engine mount control solenoid valve 2-pin connector. (Scheme 45) If there is no noticeable change in idle RPM when engine mount control solenoid valve 2-pin connector is disconnected, go to next step. If there is a noticeable change in idle RPM when engine mount control solenoid valve 2-pin connector is disconnected, engine mount control system is operating properly. Reconnect engine mount control solenoid valve 2-pin connector.
3. Place transaxle in Neutral or Park. Disconnect engine mount control solenoid valve 2-pin connector. Measure voltage of Black/Yellow wire between body ground and engine mount control solenoid valve 2-pin connector terminal No. 2. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Black/Yellow wire between engine mount control solenoid valve 2-pin connector and No. 6 (15-amp) fuse in driver's underdash fuse/relay box. See WIRING DIAGRAMS article.
4. Measure voltage across both terminals (Black/Yellow wire and Green/White wire) of engine mount control solenoid valve 2-pin connector. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Green/White wire between engine mount control solenoid valve and PCM connectors. See WIRING DIAGRAMS article. If Green/White wire is okay, substitute known-good PCM and retest. If battery voltage is now present, replace original PCM.
5. Increase engine speed above 1000 RPM and measure voltage across both terminals (Black/Yellow wire and Green/White wire) of engine mount control solenoid valve 2-pin connector. If battery voltage is not present, go to next step. If battery voltage is present, repair short to ground in Green/White wire between engine mount control solenoid valve and PCM connectors. See WIRING DIAGRAMS article. If Green/White wire is okay, substitute known-good PCM and retest.
6. Disconnect upper vacuum hose from engine mount control solenoid valve, and connect vacuum pump/gauge to hose. Apply vacuum to hose for 20 seconds. If engine mount holds vacuum, go to next step. If engine mount does not hold vacuum, repair or replace vacuum hose or engine mount.
7. Release vacuum from engine mount, and then apply vacuum again. If there is a noticeable change in idle RPM smoothness with or without vacuum applied, go to next step. If there is no noticeable change in idle RPM smoothness with or without vacuum applied, replace engine mount.
8. Remove vacuum pump/gauge from vacuum hose. Reconnect upper vacuum hose to engine mount control solenoid valve. Disconnect lower vacuum hose from engine mount control solenoid valve, and connect vacuum pump/gauge to hose. If vacuum is present, replace engine mount control solenoid valve. If vacuum is not present, repair engine mount control system as necessary.

Scheme 45

Odyssey

Note. Following procedure should be performed if engine vibrates excessively at idle.

1. Check vacuum lines and hoses for damage and proper connection. Repair/replace hoses as necessary. If vacuum lines and hoses are okay, start and warm engine to normal operating temperature (radiator cooling fan comes on). Allow engine to idle. If idle RPM is less than 730 RPM, go to next step. If idle RPM is not less than 730 RPM, adjust idle speed. See «ON-VEHICLE ADJUSTMENTS»(ref-16352) article.
2. Fully depress brake pedal. With transaxle in gear, have an assistant disconnect and reconnect engine mount control solenoid valve 2-pin connector. (Scheme 46) If there is no noticeable change in idle RPM when engine mount control solenoid valve 2-pin connector is disconnected, go to next step. If there is a noticeable change in idle RPM when engine mount control solenoid valve 2-pin connector is disconnected, engine mount control system is operating properly. Reconnect engine mount control solenoid valve 2-pin connector.
3. Place transaxle in Neutral or Park. Disconnect engine mount control solenoid valve 2-pin connector. Measure voltage of Black/Yellow wire between body ground and engine mount control solenoid valve 2-pin connector terminal No. 2. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Black/Yellow wire between engine mount control solenoid valve 2-pin connector and No. 6 (15-amp) fuse in driver's underdash fuse/relay box. See WIRING DIAGRAMS article.
4. Measure voltage across both terminals (Black/Yellow wire and Green/White wire) of engine mount control solenoid valve 2-pin connector. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Green/White wire between engine mount control solenoid valve and PCM connectors. See WIRING DIAGRAMS article. If Green/White wire is okay, substitute known-good PCM and retest. If battery voltage is now present, replace original PCM.
5. Increase engine speed above 1000 RPM and measure voltage across both terminals (Black/Yellow wire and Green/White wire) of engine mount control solenoid valve 2-pin connector. If battery voltage is not present, go to next step. If battery voltage is present, repair short to ground in Green/White wire between engine mount control solenoid valve and PCM connectors. See WIRING DIAGRAMS article. If Green/White wire is okay, substitute known-good PCM and retest.
6. Disconnect upper vacuum hose from engine mount control solenoid valve, and connect vacuum pump/gauge to hose. Apply vacuum to hose for 20 seconds. If engine mount holds vacuum, go to next step. If engine mount does not hold vacuum, repair or replace vacuum hose or engine mount.
7. Release vacuum from engine mount, and then apply vacuum again. If there is a noticeable change in idle RPM smoothness with or without vacuum applied, go to next step. If there is no noticeable change in idle RPM smoothness with or without vacuum applied, replace engine mount.
8. Remove vacuum pump/gauge from upper vacuum hose. Connect vacuum pump/gauge to upper port of engine mount control solenoid valve. Observe vacuum gauge reading with engine at idle and at a speed above 1000 RPM. If manifold vacuum is present at idle and decreases when engine speed is above 1000 RPM, engine mount control system is okay at this time. Check engine mount and vacuum hoses, if necessary. If manifold vacuum is not present at idle and does not decrease when engine speed is above 1000 RPM, replace engine mount control solenoid valve.

Scheme 46