Power & Ground Circuits (Frontier & Xterra)
- Start engine. If engine starts, turn ignition 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 (White/Green wire on 4-cylinder models, or White/Blue wire on V6 models) by backprobing. See Fig 1 and Fig 2
. 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 (Light Blue wire) by backprobing. 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 terminals No. 67, 72 and 117 (Black/Pink 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 harness connector. Disconnect ECM relay harness connector located near ECM. Check continuity of Black/Pink wires between ECM relay harness connector terminal No. 3 and ECM harness connector terminals No. 67, 72 and 117. See Figure. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary. If circuit is okay, go to next step.
- Measure voltage between ground and ECM relay harness connector terminals No. 2 and 5 (Light Blue wires). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See WIRING DIAGRAMS article.
- Check continuity between ECM harness connector terminal No. 4 and ECM relay harness connector terminal No. 1 (Light Green/Red wire on 4-cylinder models, or Orange/Black wire on V6 models). 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/Red wires), and terminals No. 25 and 32 (Black/Yellow wires). See Fig 2. If continuity exists, go to next step. If continuity does not exist, repair open ground circuit(s).
- 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.
Courtesy of NISSAN MOTOR CO., U.S.A.