Backup Lamps Inoperative (Manual Transmission)
BACKUP LAMPS INOPERATIVE (MANUAL TRANSMISSION)
DIAGNOSTIC FAULT INFORMATION
IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection
CIRCUIT/SYSTEM DESCRIPTION
Battery voltage is applied to the backup lamp switch when the ignition switch is in the RUN or CRANK positions. When the transmission is placed in the REVERSE position, the backup lamp switch provides battery voltage to the backup lamps. The backup lamps are permanently grounded at G402. With both power and ground the backup lamps illuminate. Once the driver moves the gear selector out of the REVERSE position, the backup lamp switch contacts open and the backup lamps turn OFF.
CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the backup lamp switch.
2. Ignition ON, verify that a test lamp illuminates between the backup lamp switch voltage supply circuit and ground at the backup lamp switch harness connector.
- If the test lamp does not illuminate, repair the backup lamp switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the underhood fuse block.
3. Ignition OFF, connect a 10-amp fused jumper between the backup lamp switch voltage supply circuit and the backup lamp voltage supply circuit at the backup lamp switch harness connector.
4. Ignition ON, observe the backup lamps. The backup lamps should illuminate.
- If the backup lamps do not illuminate, repair the backup lamp voltage supply circuit for a short to ground or an open/high resistance.
- If the backup lamp voltage supply circuit tests normal, repair the backup lamp ground circuit for a short to voltage or an open/high resistance.
5. If all circuits test normal, test or replace the backup lamp switch.
REPAIR INSTRUCTIONS
IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Backup Lamp Switch Replacement
- Underhood Electrical Center or Junction Block Replacement