GM Service Manual Online
For 1990-2009 cars only

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Action

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No

Schematic Reference: Interior Lights Dimming Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn ON the park lamps.
  3. Operate the instrument panel (I/P) dimmer switch from minimum to maximum.
  4. Turn OFF the park lamps.

Does the interior backlighting operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Do the park lamps work properly?

Go to Step 4

Go to Park Lamps Inoperative

4

  1. Turn ON the park lamps.
  2. Operate the I/P dimmer switch from minimum to maximum.

Do all of the backlight lamps illuminate?

Go to Step 10

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the component with the inoperative backlight lamp.
  3. Connect a test lamp between the backlight lamps control circuit of the component with the inoperative backlight lamp and the ground circuit of the component with the inoperative backlight lamp.
  4. Turn ON the ignition, with the engine OFF.
  5. Operate the I/P dimmer switch from minimum to maximum.

Does the test lamp illuminate?

Go to Step 11

Go to Step 6

6

Test the backlight lamps control circuit for a high resistance, an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 7

7

Test the ground circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 8

8

Test the instrument panel lamp fuse supply voltage - 1 circuit of the of the dash integration module (DIM) for a high resistance, an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 9

9

Inspect for poor connections at the harness connector of the DIM or at the harness connector of the door module that controls the backlight of the component with the inoperative backlighting. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 14

10

Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 13

11

Inspect for poor connections at the harness connector of the component with inoperative backlighting lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

12

  1. Replace the inoperative backlight bulbs in the component if they are replaceable. See the appropriate systems operation and description.
  2. If the bulb is not replaceable replace the component with inoperative backlighting lamps.

Did you complete the replacement?

Go to Step 15

--

13

Replace the DIM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

--

14

Replace the controlling module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

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15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2