CAN

ECM BRANCH LINE CIRCUIT

Diagnosis Procedure


1. CHECK CONNECTOR

1.Turn the ignition switch OFF.
2.Disconnect the battery cable from the negative terminal.
3.Check the following terminals and connectors for damage, bend and loose connection (unit side and connector side).
- ECM
-Harness connector M30 and PCB harness side connector
Is the inspection result normal?
YES- GO TO 2.
NO- Repair the terminal and connector.

2. CHECK HARNESS FOR OPEN CIRCUIT

1.Disconnect the connector of ECM.
2.Check the resistance between the ECM harness connector terminals.
-VQ-37VHR





-VK-56VD





Is the measurement value within the specification?
YES- GO TO 3.
NO- GO TO 4.

3. CHECK POWER SUPPLY AND GROUND CIRCUIT

Check the power supply and the ground circuit of the ECM. Refer to the following.
- VQ-37VHR: Power Supply And Ground Circuit
- VK-56VD: Power Supply And Ground Circuit
Is the inspection result normal?
YES (Present error)-Replace the ECM. Refer to the following.
- VQ-37VHR: Service and Repair
- VK-56VD: Service and Repair
YES (Past error)-Error was detected in the ECM branch line.
NO- Repair the power supply and the ground circuit.

4. CHECK HARNESS CONTINUITY (OPEN CIRCUIT)

1.Disconnect the harness connector M30.
2.Check the continuity between the ECM harness connector and the harness connector.
-VQ-37VHR





-VK-56VD





Is the inspection result normal?
YES- Replace the PCB harness.
NO (VQ-37VHR)-Repair the harness between the ECM harness connector M107 and the harness connector M30.
NO (VK-56VD)-Repair the harness between the ECM harness connector M160 and the harness connector
M30.