41-2

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. 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 a PGM-FI system and VSA system DTCs.

Is there a DTCs?
YES - Go to the indicated DTCs troubleshooting.

NO - Go to step 4.


4. Clear the DTC with the HDS.

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

Is DTCs 41-1 and/or 41-2 indicated?
YES - Go to step 6.

NO - Intermittent failure, the system is OK at this time.


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

7. Disconnect VTM-4 control unit connector A (22P), and the VSA modulator-control unit 46P connector.

8. Jump the SCS line with the HDS.

9. Disconnect PCM connector A (49P).

10. Connect PCM connector terminal A48 to body ground with a jumper wire.






11. Check for continuity between VTM-4 control unit connector terminal A11 and body ground.

Is there continuity?
YES - Go to step 12.

NO - Repair open in the wires between VTM-4 control unit connector terminal A11 and PCM connector terminal A48.






12. Remove the jumper wire from PCM connector A (49P).

13. Connect the VSA modulator-control unit 46P connector terminal No. 39 to body ground with a jumper wire.






14. Check for continuity between VTM-4 control unit connector terminal A11 and body ground.

Is there continuity?
YES - Go to step 15.

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






15. Remove the jumper wire from the VSA modulator-control unit 46P connector.

16. connector PCM connector terminal A49 to body ground with a jumper wire.






17. Check for continuity between VTM-4 control unit connector terminal A22 and body ground.

Is there continuity?
YES - Go to step 18.

NO - Repair open in the wires between VTM-4 control unit connector terminal A22 and PCM connector terminal A49.






18. Remove the jumper wire from PCM connector A (49P).

19. Connector the VSA modulator-control unit 46P connector terminal No. 38 to body ground with a jumper wire.






20. Check for continuity between VTM-4 control unit connector terminal A22 and body ground.

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 open in the wires between VTM-4 control unit connector terminal A22 and the VSA modulator-control unit 46P connector terminal No. 38.