Backup Lamps Always On. Chevrolet C-Series Medium Duty Truck C6/7/8 - Mexico 2004

GM Service Manual Online

For 1990-2009 cars

Makes 🢒 Chevrolet 🢒 2004 🢒 C-Series Medium Duty Truck C6/7/8 - Mexico 🢒 Body 🢒 Lighting Systems 🢒 Backup Lamps Always On

Backup Lamps Always On RPO MWF

Step	Action	Yes	No
Schematic Reference: Exterior Lights Schematics
1	Did you review the backup lamps operation and perform the necessary inspections?	Go to Step 2	Go to Symptoms - Lighting Systems
2	Block the wheels or set the parking brake. Place the transmission in neutral or park. Turn ON the ignition, with the engine OFF. Are the backup lamps OFF?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Turn OFF the ignition. Disconnect the reverse warning relay. Turn ON the ignition, with the engine OFF. Do the backup lamps remain illuminated?	Go to Step 5	Go to Step 4
4	Test the reverse warning relay control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 7	Go to Step 6
5	Repair the short to voltage in the backup lamps voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 7	--
6	Replace the reverse warning relay. Did you complete the replacement?	Go to Step 7	--
7	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3

Backup Lamps Always On Without RPO MWF

Step	Action	Yes	No
Schematic Reference: Exterior Lights Schematics
1	Did you review the backup lamps operation and perform the necessary inspections?	Go to Step 2	Go to Symptoms - Lighting Systems
2	Block the wheels or set the parking brake. Place the transmission in neutral or park. Turn ON the ignition switch, with the engine OFF. Are the backup lamps OFF?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Turn OFF the ignition switch. Disconnect the appropriate backup lamps switch. Turn ON the ignition switch, with the engine OFF. Are the backup lamps illuminated?	Go to Step 4	Go to Step 5
4	Repair the short to voltage in the backup lamp supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 6	--
5	Replace the appropriate backup lamp switch. Refer to Park/Neutral Backup Switch Replacement in the Automatic Transmission section or Backup Lamp Switch Replacement in the Manual Transmission section. Did you complete the replacement?	Go to Step 6	--
6	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3