GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Turn on the ignition, with the engine off.
  2. Adjust the head up display (HUD) UP then DOWN.

Does the HUD display adjust properly?

--

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

Go to Step 3

3

Inspect head up display (HUD) ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the HUD module.
  3. Connect a test lamp between the UP control circuit and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. Move the the HUD up/down switch to the UP position.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 6

5

  1. Connect a test lamp between the DOWN control circuit and a good ground.
  2. Move the the HUD up/down switch to the DOWN position.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 6

6

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

Did you find and correct the condition?

--

Go to Step 12

Go to Step 7

7

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

Did you find and correct the condition?

--

Go to Step 12

Go to Step 8

8

Inspect for poor connections at the harness connector of the HUD dimmer switch. 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 12

Go to Step 9

9

Inspect for poor connections at the harness connector of the HUD module. 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 12

Go to Step 11

10

Replace the HUD dimmer switch.

Refer to Head Up Display Switch Replacement .

Is the replacement complete?

--

Go to Step 12

--

11

Replace the HUD module.

Refer to Head Up Display Module Replacement .

Did you complete the repair?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2