Engine Controls - System/component Tests 3.0: Diagnosis Nissan Maxima A32

POWER STEERING OIL PRESSURE SWITCH SYSTEM TEST

1. Start engine and bring to operating temperature. Measure voltage between ECM harness connector terminal No. 39 (Green wire) and ground. Turn steering wheel quickly; approximately zero volts should be present. When steering wheel is not being turned, battery voltage should be present. If voltage is not as specified, go to next step. If voltage is as specified, system is functioning properly.
2. Stop engine. Disconnect Idle Air Control (IAC) valve. Turn ignition on. Check voltage between ground and IAC valve terminal No. 1 (Red/Yellow wire).
3. Battery voltage should be present. If battery voltage is present, go to step 4). If battery voltage is not present, check 10-amp fuse, harness and connectors between IAC valve and fuse.
4. Turn ignition off. Disconnect power steering oil pressure switch harness connector. Check continuity between IAC valve terminal No. 2 (Green wire) and power steering oil pressure switch harness connector terminal No. 1. Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open Green wire or connectors.
5. Turn ignition off. Disconnect power steering oil pressure switch harness connector. Check continuity between power steering pressure switch harness connector terminal No. 2 (Black wire) and ground. Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open Black wire or connectors.
6. Disconnect and inspect ECM harness connector. Check continuity between ECM harness connector terminal No. 39 (Green wire) and power steering oil pressure switch harness connector terminal No. 1. Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open Green wire or connectors.
7. Check power steering pressure switch. See POWER STEERING OIL PRESSURE SWITCH. Replace switch if necessary. If switch is okay, check harness and connectors for pushed-out, bent, damaged or corroded terminals. Repair harness or connectors as necessary.

FUEL PUMP SYSTEM TEST

1. Turn ignition on. With fingers, pinch fuel feed hose at fuel filter. Fuel pressure pulsation should be felt for 5 seconds after ignition is turned on. If pulsation is not felt, go to next step. If pulsation is felt, system is functioning properly.
2. Turn ignition off. Disconnect fuel pump relay. Fuel pump relay is located on left kick panel. Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 (Brown wire) and No. 3 (Black/White wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 10-amp fuse No. 17 and 15-amp fuse No. 32 in fuse box. Check harness continuity between fuses and fuel pump relay. Repair or replace as necessary.
3. Turn ignition off. Disconnect fuel pump harness connector and dropping resistor harness connector (located on left side of trunk). Check continuity as follows: Between fuel pump relay harness connector terminal No. 5 (Black/Yellow wire) and fuel pump harness connector terminal No. 1 (Black/Yellow wire). Between fuel pump harness connector terminal No. 2 (Green/Red wire) and dropping resistor terminal No. 2 (Green/Red wire). Continuity should exist in both checks. If continuity exists in both checks, go to next step. If continuity does not exist in either check, repair appropriate harness or connectors.
4. Ensure ignition is off. Disconnect ECM harness connector. ECM is located under center of instrument panel (connector is on driver's side). Check continuity between ECM harness connector terminal No. 11 (Black/Pink wire) and fuel pump relay harness connector terminal No. 2 (Black/Pink wire), and between ECM terminal No. 15 (Black/Pink wire) and fuel pump control module harness connector terminal No. 4 (Black/Pink wire). Continuity should exist.
5. Ensure ignition is off. Disconnect ECM harness connector. ECM is located under center of instrument panel (connector is on driver's side). Check continuity between fuel pump relay harness connector terminal No. 2 (Black/Pink wire) and ECM harness connector terminal No. 11 (Black/Pink wire). If continuity exists, go to next step. If continuity does not exist, check harness between ECM and relay.
6. Check fuel pump relay. See RELAYS under RELAYS & SOLENOIDS. Also check fuel pump. See FUEL PUMP. If necessary, replace fuel pump relay or fuel pump. If fuel pump relay and fuel pump are okay, disconnect and inspect harness and connectors for pushed-out, bent, damaged or corroded terminals. Repair harness or connectors as necessary.

FUEL INJECTOR TEST

Note. A fault in fuel injector circuit should set DTC P0170, DTC P0171, DTC P0172, DTC P0173, DTC P0174 or DTC P0175. To test system, see diagnostic procedures in appropriate TESTS W/CODES article.

1. With engine running, listen for clicking sound at each injector. If clicking sound is present at each injector, system is functioning properly. If clicking sound is not present, go to next step.
2. Turn ignition (engine) off. Disconnect injector harness connector(s). Turn ignition on. Measure voltage between ground and injector harness connector Red wire(s). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 10-amp fuse, harness, and connectors between battery and injector(s). Repair or replace as necessary.
3. Check fuel injector(s). See FUEL INJECTOR. If fuel injectors are okay, check ECM terminals, harness, and connector terminals for damage or corrosion. Repair or replace as necessary.

FAST IDLE CONTROL DEVICE (FICD) SYSTEM TEST

1. Start engine and warm to operating temperature. Check idle speed. See SPECIFICATIONS article. Adjust idle speed if necessary. See ADJUSTMENTS article. Turn A/C switch and blower fan switch on. Idle speed should increase. If idle speed does not increase, go to next step. If idle speed increases, system is functioning properly.
2. Ensure A/C compressor functions normally. If compressor is not functioning, repair A/C system as necessary. If compressor is functioning, go to next step.
3. Turn ignition (engine) off. Disconnect FICD solenoid harness connector. Start engine and let it idle. Measure voltage between ground and FICD harness connector terminal Yellow/Black wire. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 7.5-amp fuse. If fuse is okay, repair open harness or connectors between fuse, A/C relay, and FICD solenoid.
4. Turn ignition (engine) off. Disconnect FICD solenoid harness connector. Check continuity between ground and FICD solenoid harness connector Black wire. Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open Black wire or connectors. On automatic A/C equipped models, ensure automatic A/C control unit is functioning normally.
5. Check FICD solenoid. See FAST IDLE CONTROL DEVICE (FICD) SOLENOID. If FICD solenoid is okay, check ECM terminals, harness, and connector terminals for pushed-out, damaged, or corroded terminals. Repair or replace as necessary.

START SIGNAL SYSTEM TEST

1. Turn ignition switch to START position. Measure voltage between ground and ECM harness connector terminal No. 20. See START CIRCUIT WIRE COLOR & ECM TERMINAL IDENTIFICATION table for wire color. (Схема №1) Battery voltage should be present in START position ONLY. Zero volts should be present in any other ignition switch position.
2. If voltage is not as specified, check 7.5 amp fuse in fuse block. If fuse is okay, repair circuit between ECM and fuse block. If voltage is as specified, check ECM terminals, harness, and connector terminals for damage or corrosion. Repair as necessary.

START CIRCUIT WIRE COLOR & ECM TERMINAL IDENTIFICATION (1)