DTC 78-1

DTC 78-1: VTM-4 Control Unit nit
1. Clear the DTC.
2. Test-drive the vehicle, and watch the VTM-4 indicator.
Does the VTM-4 indicator come on?
YES-Go to step 3.
NO-The system is OK at this time.
3. Check the battery.
Is the specified battery installed, and is it fully charged?
YES-Go to step 4.
NO-Replace the battery.
4. Watch the charging system indicator.
Does the charging system indicator come on with the ignition switch ON (II), and after the engine starts, does the indicator go off?
YES-Go to step 5.
NO-Check the charging system.
5. 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.