GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Courtesy Lamps Inoperative with Instrument Panel Dimmer Switch

Step

Action

Value(s)

Yes

No

DEFINITION: The courtesy lights do not turn on when the IP dimmer switch is in the DOME position. The courtesy lights turn on when any door is open.

1

Was the Interior Lights System Check performed?

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Go to Step 2

Go to Interior Lamps System Check

2

Was the BCM Diagnostic System Check performed?

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Go to Step 3

Go to Diagnostic System Check - Body Control System in Body Control System

3
  1. Turn the IP dimmer switch to the DOME position.
  2. Use a test light in order to backprobe between B+ and the body control module (BCM) connector C2 terminal C2 .

Does the test light illuminate?

--

Go to Step 4

Go to Step 5

4
    • Inspect the BCM connector C2 terminal C2 for a poor terminal contact. Perform repairs as needed.
    • If the BCM connector C2 terminal C2 is OK, then replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

Go to Step 10

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5
  1. Disconnect the headlamp switch electrical connector.
  2. Using a test light probe between B+ and the headlamp switch harness connector terminal A.

Does the test light illuminate?

--

Go to Step 6

Go to Step 7

6
  1. Disconnect the BCM connector C2.
  2. Using a DMM measure the resistance between the BCM harness connector C2 terminal C2 and the headlamp switch harness connector terminal B.

Is the resistance less than the specified value?

2 ohms

Go to Step 8

Go to Step 9

7

Repair the poor connection or an open in circuit 1450.

Is the repair complete?

--

Go to Step 10

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8

Replace the headlamp switch assembly.

Is the repair complete?

--

Go to Step 10

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9

Repair the poor connection or an open in circuit 156.

Is the repair complete?

--

Go to Step 10

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10
  1. Turn the ignition switch to the OFF position.
  2. Reinstall the connectors and components that were removed.
  3. Turn the ignition switch to the RUN position for 6 seconds.
  4. Turn the ignition switch to the OFF position.
  5. Remove the MALL PGM fuse.
  6. Turn the ignition switch to the ACC position. (The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle.)
  7. Within one second, turn the ignition switch from the ACC position, to the OFF position, then back to the ACC position. (The BCM sounds any DTCs stored.)

Are there any BCM DTCs present?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Interior Lamps System Check