Power & Ground Circuits (Quest)
- Start engine. If engine starts, turn engine off and go to next step. If engine does not start, turn ignition off and on. Measure voltage between ground and ECM terminal No. 24 (Blue/Yellow wire) by backprobing. See Figure and Fig 1
. If battery voltage exists, go to step 8. If battery voltage does not exist, repair open or short circuit. See WIRING DIAGRAMS article.
- Measure voltage between ground and ECM terminal No. 80 (Yellow wire) by backprobing. See Figure. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See WIRING DIAGRAMS article.
- While turning ignition on and off, measure voltage between ground and ECM harness connector terminals No. 67, 72 and 117 (Black/White wires) by backprobing. Battery voltage should exist for a few seconds after turning ignition off. If voltage is as specified, go to step 8. If battery voltage does not exist, go to next step. If battery voltage exists for more than a few seconds, go to step 7.
- Disconnect ECM relay harness connector. See Fig 1. Measure voltage between ground and ECM relay harness connector terminals No. 2 and 3 (Red wires). See Figure. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See WIRING DIAGRAMS article.
- Disconnect ECM harness connector. Check continuity of White/Green wire between ECM harness connector terminal No. 4 and ECM relay harness connector terminal No. 1. See Figure and Figure
. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary. If circuit is okay, go to next step.
- Check continuity of Black/White wires between ECM relay harness connector terminal No. 5 and ECM harness connector terminals No. 67, 72 and 117. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary. If circuit is okay, go to next step.
- Check ECM relay. See RELAYS under RELAYS & SOLENOIDS. Replace, if necessary and retest system. If relay is okay, go to next step.
- Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 10, 19, 116 and 124 (Black wires) and terminals No. 25 and 32 (Black/Red wires). Continuity should exist. Also, check circuits for short to voltage. Repair circuit(s) as necessary. If all circuits are okay, go to next step.
- No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
Courtesy of NISSAN MOTOR CO., U.S.A.