GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Head Up Display Schematics

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. Adjust the head-up display (HUD) dimmer switch to full intensity, then back to full dim.

Does the HUD dim properly?

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

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the HUD display connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the HUD dim slider circuit and B+ at the instrument panel cluster (IPC) . Refer to Circuit Testing in Wiring Systems.
  5. Adjust the HUD to full intensity, then back to full dim.

Does the test lamp go from full intensity then dim?

Go to Step 6

Go to Step 4

4

Test the HUD dim slider circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 5

5

Replace the HUD dimmer switch. Refer to Switch Replacement - Ignition and Start, DIC Display and HUD Dimmer .

Did you find and correct the condition?

Go to Step 8

Go to Step 7

6

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

Did you complete the replacement?

Go to Step 8

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7

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

Did you complete the replacement?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2