26-1

VTM-4 DTC Troubleshooting: 26-1

DTC 26-1: VSA Modulator-Control Unit or Wire Harness

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. Clear the DTC with the HDS.

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

Is DTC 26-1 indicated?
YES - Go to step 5.

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


5. Check for DTCs in the VSA system with the HDS.

Are there any VSA DTCs indicated?
YES - Go to the indicated DTCs troubleshooting.

NO - Go to step 6.


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

7. Raise the vehicle on a lift, and make sure it is securely supported.

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

9. Measure the voltage between VTM-4 control unit connector terminals A3, A5, A7, and A9 to body ground while rotating the appropriate wheel one rotation a second.





Are all four readings about 2.0 V to 3.0 V?
YES - Check for poor connections or loose terminals at the VTM-4 control unit. 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 - Check for poor connections or loose terminals between the VTM-4 control unit and the VSA modulator-control unit. If the connections are OK, replace the VSA modulator-control unit. Service and Repair