GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Bonneville 🢒 Body and Accessories 🢒 Instrument Panel, Gages, and Console 🢒 Head Up Display (HUD) Intensity Does Not Vary

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests for the proper operation of the circuit in the low voltage range.

    2.

  2. Tests for the proper operation of the circuit in the high voltage range.

Step

Action

Value(s)

Yes

No

Schematic Reference: Head Up Display Schematics

1

Did you perform the Head Up Display Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Head Up Display

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, perform the VF Dim in the HUD Special Functions.

Does the HUD intensity increase when you select Brighter and decrease when you select Dimmer?

--

Go to Step 3

Go to Step 13

3
  1. With a scan tool, observe the VF Dim parameter in the HUD data list.
  2. Adjust the HUD dimmer switch from full dim (not OFF) to full intensity.

Does the scan tool indicate that the VF Dim parameter varies within the specified range?

2-12 V

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

Go to Step 4

4

With a scan tool, observe the VF Dim parameter.

Does the scan tool indicate that the VF Dim parameter is near the specified value?

0 V

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the ignition 3 voltage circuit of the HUD switch and the VF dimming signal circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the VF Dim parameter.

Does the scan tool indicate that the VF Dim parameter is near the specified value?

B+

Go to Step 6

Go to Step 8

6
  1. Turn OFF the ignition.
  2. Disconnect the HUD switch.
  3. Connect a test lamp between the ignition 3 voltage circuit of the HUD switch and the ground circuit of the HUD switch.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 11

7

Test the VF dimming signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

8

Test the VF dimming signal circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 10

9

Inspect for poor connections at the harness connector of the HUD 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 14

Go to Step 12

10

Inspect for poor connections at the harness connector of the HUD. 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 14

Go to Step 13

11

Repair the open or the high resistance in the ground circuit of the HUD switch. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 14

--

12

Replace the HUD switch. Refer to Head Up Display Switch Replacement .

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the HUD. Refer to Head Up Display Module Replacement .

Did you complete the replacement?

--

Go to Step 14

--

14

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2