GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect the instrument cluster head-up display (HUD) dimmer switch.
  2. Turn the ignition switch to the RUN position.
  3. Use a J 39200 digital multimeter (DMM) in order to measure the voltage between the instrument cluster HUD dimmer switch harness connector terminals A and G.

Is the measured voltage within the specified value?

9-14 V

Go to Step 3

Go to Step 2

2

  1. Repair the open or the poor connection in CKT 1550 between the instrument cluster HUD dimmer switch harness connector terminal G and G200.
  2. Inspect the system.

Is the repair complete?

--

System OK

--

3

  1. Turn the park lamps ON.
  2. Use a J 39200 digital multimeter (DMM) in order to measure the voltage between the instrument cluster HUD dimmer switch harness connector terminals G and B.

Is the voltage within the specified range?

9-14 V

Go to Step 4

Go to Interior Lights Dimming System Check in Lighting Systems

4

  1. Replace the illumination bulbs or the instrument cluster head-up display dimmer switch, as needed. Refer to Head Up Display Switch Replacement .
  2. Inspect the system.

Is the repair complete?

--

System OK

--