For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform Backup Lamps Diagnostic System Check? | -- | Go to Step 2 | Go to Backup Lamp System Check
2 |

1. Disconnect one of the following connectors:

• | (Automatic) The transaxle range switch connector

• | (Manual) The backup lights switch connector

2. Turn the ignition switch to the RUN position.
3. Connect a test lamp between terminal B and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 8

3 |

1. Place the transaxle in reverse.
2. Reconnect the transaxle range switch or the backup lights switch.
3. Disconnect the left side or the right side backup light.
4. Turn the ignition switch to RUN.
5. Connect a test lamp between terminal B (Buick/Oldsmobile) or terminal C (Pontiac) and ground.

Does the test lamp light?

--

Go to Step 4

Go to Step 5

4 | Repair an open in CKT 150. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Backup Lamp System Check | --
5 | Test CKT 24 for an open. Did you find an open in CKT 24? | -- | Go to Step 6 | Go to Step 7
6 | Repair an open in CKT 24. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Backup Lamp System Check | --
7 | Adjust or replace the following components:

• | (Automatic) The PNP Switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transaxle - 4T40-E

• | (Manual) The backup lights switch

Did you complete the repair?

--

Go to Backup Lamp System Check

--

8 | Repair an open in CKT 439. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Backup Lamp System Check | --