For 1990-2009 cars

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

1. Ensure the front dome lamp switch is in the OFF position.
2. Close all of the vehicle doors.
3. Place the front dome lamp switch in the DOOR position.
4. Wait 30 seconds.

Do the courtesy lamps operate as expected?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3 | Do the courtesy lamps remain on with the front dome lamp switch in the OFF position? | Go to Step 7 | Go to Step 24
4 |

1. Ensure the front dome lamp switch is in the DOOR position.
2. Close all of the vehicle doors.
3. Use the scan tool in order to command the courtesy lamps OFF.

Do the courtesy lamps turn OFF when commanded?

Go to Step 5

Go to Step 8

5 |

1. Close all of the vehicle doors.
2. With a scan tool, observe the Driver Door Switch, Passenger Door Switch, and the Lift- gate Ajar Switch parameters in the data list.

Does the scan tool display that all parameters are High?

Go to Step 14

Go to Step 6

6 | Does the scan tool display that the Passenger Door Switch parameter is Low? | Go to Step 10 | Go to Step 9
7 | Disconnect the front dome lamp switch. Is the rear courtesy lamp illuminated? | Go to Step 15 | Go to Step 13
8 | Test the courtesy lamps switch signal circuit for a short to ground. Did you find and correct the condition? | Go to Step 19 | Go to Step 14
9 | While monitoring the parameters, disconnect the connector of the switch that indicates a Low parameter. Does the scan tool display a parameter change to High when a switch is disconnected? | Go to Step 17 | Go to Step 11
10 | While monitoring the parameter, disconnect each passenger door jamb switch one at a time. Does the scan tool display a parameter change to High when one of the passenger door jamb switches is disconnected? | Go to Step 17 | Go to Step 12
11 | Test the ajar switch signal circuit for a short to ground. Did you find and correct the condition? | Go to Step 19 | Go to Step 14
12 | Test the passenger door ajar switch signal circuit for a short to ground Did you find and correct the condition? | Go to Step 19 | Go to Step 14
13 | Inspect for poor connections at the harness connector of the Map lamp switch. Did you find and correct the condition? | Go to Step 19 | Go to Step 16
14 | Inspect for poor connections at the harness connector of the body control module (BCM). Did you find and correct the condition? | Go to Step 19 | Go to Step 18
15 | Repair the ground circuit of the rear dome lamp for a short to ground. Did you complete the repair? | Go to Step 19 | --
16 | Replace the map lamp switch. Did you complete the replacement? | Go to Step 19 | --
17 | Replace the inoperative ajar switch. Did you complete the replacement? | Go to Step 19 | --
18 | Replace the BCM. Refer to Body Control Module Replacement . Did you complete the replacement? | Go to Step 19 | --
19 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2