GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go To Diagnostic System Check - Lighting Systems in Lighting system.

2

  1. Place the IP dimmer switch in the FULL BRIGHT position.
  2. Place the headlamp switch in the PARK position

Are both steering wheel control switches illuminated?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring System.

Go to Step 3

3

Is one steering wheel control switch illuminated?

Go to Step 5

Go to Step 4

4

  1. Remove both steering wheel control switches.
  2. Probe the IP lamp dimming feed circuit of each switch with a test lamp connected to a known good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

5

  1. Remove the appropriate switch.
  2. Probe the IP lamp dimming feed circuit of the appropriate switch with a test lamp connected to a known good ground.Probe the IP lamp dimming feed circuit of the appropriate switch with a test lamp connected to a known good ground

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6

Test for an open or high resistance condition in the IP dimming lamp feed circuit.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7

Test for an open or high resistance condition in the IP dimming lamp ground circuit.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

8

Replace the appropiate switch refer to Steering Wheel Control Switches Replacement in Lighting Systems.

Did you complete the repair?

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2