Nissan Sentra Service Manual: Power supply and ground circuit

Diagnosis Procedure

1.CHECK FUSE

Check that the following fuse is not fusing.

Is the fuse fusing? YES >> Replace the fuse after repairing the applicable circuit.

NO >> GO TO 2.

2.CHECK GROUND CONNECTION

1. Turn ignition switch OFF
2. Check ground connection E9 and E15. Refer to GI-42, "Circuit Inspection".

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace ground connection.

3.CHECK ECM GROUND CIRCUIT

1. Disconnect ECM harness connectors.
2. Check the continuity between ECM harness connector and ground.

Is the inspection result normal? YES >> GO TO 4.

NO >> Repair or replace error-detected parts.

4.CHECK ECM POWER SUPPLY (MAIN)-1

1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check the voltage between ECM harness connector terminals.

Is the inspection result normal? YES >> GO TO 5.

NO >> GO TO 6.

5.CHECK ECM POWER SUPPLY (MAIN)-2

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check the voltage between ECM harness connector terminals as per the following.

Is the inspection result normal? YES >> GO TO 9.

NO >> GO TO 7.

6.CHECK ECM POWER SUPPLY (MAIN) CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connectors.
3. Disconnect IPDM E/R harness connector.
4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground.

Is the inspection result normal? YES >> Perform the trouble diagnosis for power supply circuit.

NO >> Repair or replace error-detected parts.

7.CHECK ECM RELAY CONTROL SIGNAL

Check the voltage between ECM harness connector terminals as per the following.

Is the inspection result normal? YES >> Check Intermittent incident. Refer to GI-39, "Intermittent Incident".

NO >> GO TO 8.

8.CHECK ECM RELAY CONTROL SIGNAL CIRCUIT

1. Turn ignition switch OFF
2. Disconnect ECM harness connector.
3. Disconnect IPDM E/R harness connector
4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground and to power.

Is the inspection result normal? YES >> Replace IPDM E/R. Refer to PCS-58, "Removal and Installation" (with intelligent key), PCS-58, "Removal and Installation" (without intelligent key).

NO >> Repair or replace error-detected parts.

9.CHECK IGNITION SWITCH SIGNAL

1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals.

Is the inspection result normal? YES >> GO TO 11.

NO >> GO TO 10.

10.CHECK IGNITION SWITCH SIGNAL CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect IPDM E/R harness connector.
4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground and to power.

Is the inspection result normal? YES >> Perform the trouble diagnosis for power supply circuit.

NO >> Repair or replace error-detected parts.

11.CHECK ECM POWER SUPPLY (BACK-UP)

Check the voltage between ECM harness connector terminals.

Is the inspection result normal? YES >> Check Intermittent Incident. Refer to GI-39, "Intermittent Incident".

NO >> GO TO 12.

12.CHECK ECM POWER SUPPLY (BACK-UP) CIRCUIT

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect IPDM E/R harness connector.
4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground.

Is the inspection result normal? YES >> Perform the trouble diagnosis for power supply circuit.

NO >> Repair or replace error-detected parts.