Auxiliary Air Control (AAC) Valve System Test (Maxima VG30E)
- Start engine and bring to operating temperature. Turn diagnostic test mode selector on ECM fully clockwise. ECM is located under center of instrument panel. Turn air conditioner switch on. Engine speed should drop. Go to next step.
- Turn air conditioner switch off. Turn diagnostic mode selector on ECM fully counterclockwise. Turn air conditioner switch on. Engine speed should not change. If engine speed dropped in step 1) and did not change in step 2), system is functioning properly. If not, go to next step.
- Turn air conditioner switch off. Measure voltage between ground and ECM harness connector terminals No. 4 (Yellow/Black wire),No. 5 (Yellow/Red wire), No. 14 (Yellow wire) and No. 15 (Yellow/Blue wire). See Figure and Figure . Race engine under no-load. Voltage should change when racing engine. Stop engine and turn ignition on.
- Measure voltage between ground and ECM harness connector terminals No. 4 (Yellow/Black wire), No. 5 (Yellow/Red wire), No. 14 (Yellow wire) and No. 15 (Yellow/Blue wire). Battery voltage should be present. If voltage is not as specified, go to next step. If voltage is as specified, ensure ECM harness connector is connected properly.
- Turn ignition off. Disconnect AAC valve harness connector. Turn ignition on. Measure voltage between ground and AAC harness connector terminal White/Black wire (2 wires). Battery voltage should be present. If battery voltage is present, go to step 7). If battery voltage is not present, go to next step.
- Turn ignition off. Ensure AAC valve harness connector is disconnected. Turn ignition on. Check continuity between AAC valve harness connector White/Black wire and battery positive White/Red wire. Continuity should exist. If continuity does not exist, check Brown fusible link located in fusible link and relay box next to battery. Repair or replace as necessary. Check ECM (ECCS) relay located in fusible link and relay box next to battery. See RELAYS under RELAYS & SOLENOIDS. Repair/replace as necessary. If ECM relay and Brown fusible link are okay, repair open in harness. See WIRING DIAGRAMS article.
- Turn ignition off. Disconnect ECM harness connector. Check continuity between ECM harness connector terminal No. 4 (Yellow/Black wire) and AAC valve harness connector Yellow/Black wire. Check continuity between ECM harness connector terminal No. 5 (Yellow/Red wire) and AAC valve harness connector Yellow/Red wire. Check continuity between ECM harness connector terminal No. 14 (Yellow wire) and AAC valve harness connector Yellow wire.
- Check continuity between ECM harness connector terminal No. 15 (Yellow/Blue wire) and AAC valve harness connector Yellow/Blue wire. Continuity should exist in all checks. If continuity does not exist, repair open in appropriate wire. If continuity exists, check AAC valve. See AUXILIARY AIR CONTROL (AAC) VALVE TEST (MAXIMA VG30E).