DTC 78-1

DTC 78-1: VTM-4 Control Unit

NOTE: Before you troubleshoot, review the general troubleshooting information.

1. Turn the ignition switch ON (II).
2. Clear the DTCs with the HDS.
3. Test-drive the vehicle, and check for DTCs with the HDS.
Is DTC 78-1 indicated?
YES - Go to step 4.
NO - Intermittent failure, the system is OK at this time.
4. Check the battery.
Is the specified battery installed, and is it fully charged?
YES - Go to step 5.
NO - Charge or replace the battery.
5. Check the charging system indicator.
Does the charging system indicator come on with ignition switch ON (II), and after the engine starts, does the indicator go off?
YES - Go to step 6.
NO - Troubleshoot the charging system.
6. Check for installation of any aftermarket CB or Ham radios which may cause an RF signal interference.
Is there an aftermarket radio installed?
YES - Disconnect the aftermarket radio, and retest.
NO - Check for loose terminal fit in the VTM-4 control unit connectors. If it is normal, replace the VTM-4 control unit.