Diesel Data: Automotive Repair

41-1




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

DTC 41-1, 41-2:

CAN Communication (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. Check for a PGM-FI system and VSA system DTCs.

Are there any DTC's indicated?

YES -

Go to the indicated DTCs troubleshooting.�

NO -

Go to step 3.

3. Clear the DTC with the HDS.

4. Test-drive the vehicle, and check for DTCs with the HDS.

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

YES -

Go to step 5.

NO -

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

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

6. Disconnect VTM-4 control unit connector A (22P).

7. Jump the SCS line with the HDS.

8. Disconnect PCM connector A (49P).

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





Is there continuity?

YES -

Go to step 10.

NO -

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

10. Disconnect the VSA modulator-control unit 46P connector.

11. Check for continuity between VTM-4 control unit connector terminal A11 and VSA modulator-control unit 46P connector terminal No. 39.





Is there continuity?

YES -

Go to step 12.

NO -

Repair an open in the wire between VTM-4 control unit connector terminal A11 and the VSA modulator-control unit 46P connector terminal No. 39.�

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





Is there continuity?

YES -

Go to step 13.

NO -

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

13. Check for continuity between VTM-4 control unit connector terminal A22 and VSA modulator-control unit 46P connector terminal No. 38.





Is there continuity?

YES -

Check for poor connections or loose terminals at the VTM-4 control unit connectors, PCM, VSA modulator-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 wire between VTM-4 control unit connector terminal A22 and the VSA modulator-control unit 46P connector terminal No. 38.�