Diesel Data: Automotive Repair

Power Supply And Ground Circuit




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 E21 and E38. 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)-I

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)-II

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. 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. IPDM E/R (With I-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. 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.