The head-up display (HUD) is a display system that optically projects vehicle information onto the windshield. The HUD has an electric tilt adjust that is controlled by the up and down switches. Operating these switches directs the motor to move the HUD image up or down on the windshield. The HUD is also equipped with automatic dimming. Dimming is also controlled by a HUD dimmer switch. All three switches control the HUD by grounding the HUD switch input signals to ground. The dimmer switch uses a variable resistor to control HUD intensity where the lower the resistance, the brighter the HUD display.

Schematic Reference

Head Up Display Schematics

Connector End View Reference

Displays and Gages Connector End Views

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Ignition OFF, disconnect the harness connector at the HUD module.
2. Ignition ON, dimmer switch at the high intensity position, verify that a test lamp illuminates between the battery positive voltage circuit and the dimmer switch display signal circuit.

⇒	If the test lamp does not illuminate, test the dimmer switch display signal circuit and the dimmer switch ground circuit for an open/high resistance. If the circuits test normal, replace the HUD switch.

3. Ignition ON, connect a test lamp between the battery positive voltage circuit and the image up signal circuit. The test lamp should illuminate when the up button is pressed and should not illuminate when the up button is not pressed.

⇒	If the test lamp does not illuminate when the button is pressed, test the up signal circuit for an open/high resistance. If the circuit tests normal, replace the HUD switch.

⇒	If the test lamp does illuminate when the button is not pressed, test the up signal circuit for a short to ground. If the circuit tests normal, replace the HUD switch.

4. Ignition ON, connect a test lamp between the battery positive voltage circuit and the image down signal circuit. The test lamp should illuminate when the down button is pressed and should not illuminate when the down button is not pressed.

⇒	If the test lamp does not illuminate when the button is pressed, test the down switch signal circuit for an open/high resistance. If the circuit tests normal, replace the HUD switch.

⇒	If the test lamp does illuminate when the button is not pressed, test the down switch signal circuit for short to ground. If the circuit tests normal, replace the HUD switch.

5. If all circuits test normal, test or replace the HUD module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.