Backup Lamps Inoperative. Buick GL7 (Export) 2000

For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Lighting System Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Lighting Systems

2

1. Turn ON the ignition, with the engine OFF.
2. Place the gear shift selector lever in the REVERSE position.

Do both backup lamps illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3 | Did only one lamp illuminate? | Go to Step 6 | Go to Step 4

4

1. Disconnect the transaxle range switch harness connector.
2. Probe the ignition positive voltage supply circuit of the transaxle range switch with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 8

5 | Install a fused jumper across the ignition positive voltage supply circuit and the backup lamps voltage supply circuit of the transaxle range switch connector. Did the backup lamps illuminate? | Go to Step 10 | Go to Step 7
6 | Repair the open or high resistance in the inoperative back up lamp power supply or ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 11
7 | Test the backup lamps voltage supply circuit for a short to ground or open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 9
8 | Repair the open or high resistance in the ignition positive voltage supply circuit of the transaxle range switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | --
9 | Test the backup lamps ground supply circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | --
10 | Inspect the transaxle range switch, adjust and/or replace if needed. Refer to Park/Neutral Position Switch Adjustment in Automatic Transaxle. Did you complete the repair? | Go to Step 12 | --
11 | Replace the inoperative backup lamp. Refer to Tail Lamp Replacement Did you complete the repair? | Go to Step 12 | --
12 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2