GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Important: The BCM monitors the courtesy lamp relay control CKT 690 (GRY/BLK) for faults. If this circuit is open or shorted to power or ground, a DTC will set.

1

Did you perform the Interior Lamps System Check?

--

Go to Step 2

Go to Interior Lamps System Check

2

Use the scan tool in order to inspect for DTCs.

Are any DTCs present?

--

Go to Diagnostic Trouble Code (DTC) List/Type in Body Control System

Go to Step 3

3

Inspect for the following related BCM data parameters. Refer to Scan Tool Data List in Body Control System for typical values and definitions.

    • The driver door jamb switch
    • The passenger door jamb/door handle switches
    • The courtesy lamp relay
    • The inadvertent power relay
    • The dome override switch
    • The dome lamp switch

Did you find and correct a problem?

--

Go to Interior Lamps System Check

Go to Step 4

4

Disconnect the courtesy lamp relay from the body relay block.

Did the courtesy/dome lamps turn OFF?

--

Go to Step 6

Go to Step 5

5

Repair the short to ground in CKT 156.

Is the repair complete?

--

Go to Interior Lamps System Check

--

6

Replace the courtesy lamp relay.

Is the repair complete?

--

Go to Interior Lamps System Check

--