41-2

VTM-4 DTC Troubleshooting: 41-1, 41-2

DTC 41-1, 41-2:

F-CAN Malfunction (Lost Communication with Power Control Module (PCM)/VSA System)

NOTE: Before you troubleshoot, review the general troubleshooting information Initial Inspection and Diagnostic Overview.

1. Turn the ignition switch to ON (II).

2. Make sure the HDS communicates with the vehicle and the VTM-4 control unit. If it doesn't, troubleshoot the DLC circuit Testing and Inspection.

3. Check for DTCs in the PGM-FI system and VSA system with the HDS.

Are there any DTC's indicated?

YES -

Go to the indicated DTC's troubleshooting.�

NO -

Go to step 4.

4. Clear the DTC with the HDS.

5. Test-drive the vehicle.

6. Check for DTCs with the HDS.

Is DTC 41-1 and/or 41-2 indicated?

YES -

Go to step 7.

NO -

Intermittent failure, the system is OK at this time.�

7. Turn the ignition switch to LOCK (0).

8. Jump the SCS line with the HDS.

NOTE: This step must be done to prevent PCM damage.

9. Disconnect PCM connector A (49P).

10. Disconnect VTM-4 control unit connector A (20P).

11. Check for continuity between PCM connector terminal A48 and VTM-4 control unit connector terminal A11.





Is there continuity?

YES -

Go to step 12.

NO -

Repair an open in the wires between VTM-4 control unit connector terminal A11 and PCM connector terminal A48.�

12. Disconnect the VSA modulator-control unit 36P connector.

13. Check for continuity between VSA modulator-control unit 36P connector terminal No. 14 and VTM-4 control unit connector terminal A11.





Is there continuity?

YES -

Go to step 14.

NO -

Repair an open in the wires between VTM-4 control unit connector terminal A11 and VSA modulator-control 36P connector terminal No. 14.

14. Check for continuity between PCM connector terminal A49 and VTM-4 control unit connector terminal A22.





Is there continuity?

YES -

Go to step 15.

NO -

Repair an open in the wires between VTM-4 control unit connector terminal A22 and PCM connector terminal A49.�

15. Check for continuity between VSA modulator-control unit 36P connector terminal No. 1 and VTM-4 control unit connector terminal A22.





Is there continuity?

YES -

Check for poor connections or loose terminals at the VTM-4 control unit connectors. If the connections are OK, substitute a known-good VTM-4 control unit Service and Repair, and recheck. If the symptom/indication goes away with the known-good VTM-4 control unit, replace the original VTM-4 control unit Service and Repair.�

NO -

Repair an open in the wires between VTM-4 control unit connector terminal A22 and VSA modulator-control unit 36P connector terminal No. 1.�