Power & Ground Circuits (G20)
- Start engine. If engine starts, go to next step. If engine does not start, turn ignition off and on. Measure voltage between ground and ECM terminal No. 43 by backprobing. See Fig 1 and Fig 2
. If battery voltage exists, go to step 8. If battery voltage does not exist, go to next step.
- Turn ignition off. Measure voltage between ground and ECM terminal No. 67 by backprobing. See Fig 1 and Fig 2
. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See appropriate wiring diagram in WIRING DIAGRAMS article.
- Measure voltage between ground and ECM terminals No. 110 and 112 by backprobing. While observing voltmeter, turn ignition on and off. Battery voltage should exist for a few seconds after turning ignition off. After a few seconds, voltage should drop to about zero volts. 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 after ignition is turned off, go to step 7.
- Disconnect ECM and ECM relay harness connectors. See Fig 1 and Fig 3
. Check continuity of White wire between ECM relay harness connector terminal No. 3 and ECM harness connector terminals No. 110 and 112. Also check circuit for short to ground and short to voltage. Repair as necessary and retest system. If circuit is okay, go to next step.
- Measure voltage between ground and ECM relay harness connector terminals No. 1 and 5 (White/Blue wires). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See appropriate wiring diagram in WIRING DIAGRAMS article.
- Check continuity of White/Green wire between ECM relay harness connector terminal No. 2 and ECM harness connector terminal No. 31. Also check circuit for short to ground and short to voltage. Repair as necessary and retest system. If circuit is okay, go to next step.
- Check ECM relay. See RELAYS & SOLENOIDS . Replace, if necessary and retest system. If ECM relay is okay, go next step.
- Turn ignition off. Disconnect ECM harness connector. Check continuity between engine ground and ECM harness connector terminals No. 48, 57, 106 and 108. Also check circuits for short to voltage. Repair as necessary and retest system. If ground circuits are okay, go to next step.
- No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
Courtesy of NISSAN MOTOR CO., U.S.A.
Courtesy of NISSAN MOTOR CO., U.S.A.
Courtesy of NISSAN MOTOR CO., U.S.A.