GM Service Manual Online
For 1990-2009 cars only

LH/RH courtesy lamps Inoperative

Step

Action

Value(s)

Yes

No

DEFINITION: One or more of the following lamps are inoperative:

    • instrument panel courtesy lamps
    • rear compartment courtesy lamps
    • inside rearview mirror courtesy lamps

1

Were you sent here from the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Are all the courtesy lamps and the inside rearview mirror lamps inoperative?

--

Go to Step 3

Go to Step 10

3

Inspect the C/LALDL fuse #29 for an open.

Is the fuse open?

--

Go to Step 4

Go to Step 5

4

Repair the short to ground in the courtesy lamp feed circuit 740 or the data link connector battery feed circuit 1240.

Is the repair complete?

--

Go to Step 13

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5

  1. Remove the CTSY LP relay #42 in the instrument panel electrical center.
  2. Connect a fused jumper wire from the battery feed circuit 1240 to the courtesy lamp feed circuit 740 relay terminals in the instrument panel electrical center.

Do the courtesy lamps illuminate?

--

Go to Step 6

Go to Step 10

6

  1. Reinstall the CTSY LP relay #42 in the instrument panel electrical center.
  2. Disconnect the BCM connector C3.
  3. Using a fused jumper wire ground the C/LALDL relay #42 control circuit 690.

Do the courtesy lamps illuminate?

--

Go to Step 9

Go to Step 7

7

Test and repair the C/LALDL relay #42 control circuit 690 for an open or high resistance.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 8

8

Replace the C/LALDL relay #42.

Is the repair complete?

--

Go to Step 13

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9

Replace the BCM. Refer to Body Control Module Replacement and Body Control Module (BCM) Programming/RPO Configuration .

Is the repair complete?

--

Go to Step 13

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10

Test and repair the courtesy lamp feed circuit 740 for an open or high resistance.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

11

Test and repair the courtesy lamp ground circuit 150 for an open or high resistance.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

12

Replace the inoperative courtesy lamps as necessary. Refer to Instrument Panel Courtesy Lamp Bulb Replacement and Rearview Mirror Lamp Replacement .

Is the repair complete?

--

Go to Step 13

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13

  1. Clear any DTCs which may have set. Refer to Diagnostic Trouble Code (DTC) Clearing .
  2. Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Diagnostic System Check - Lighting Systems