Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The head up display (HUD) is a secondary display system capable of reflecting important vehicle information onto the windshield. The vehicle information is displayed using virtual imaging and is reflected off the windshield in front of the driver. Battery positive voltage is the main power source for the HUD system. However, the HUD system can only be enabled when the ignition is active and in the RUN position. The HUD system receives all vehicle information to be displayed via the class 2 serial data circuit. The HUD system interfaces with the HUD switch via discreet circuits. The HUD switch is a normally open switch and ground is provided from within the HUD switch when any switch press occurs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. With the ignition OFF, turn the HUD dimmer down switch to the OFF position.

⇒	If the HUD turns OFF, check for intermittent and poor connection at the harness connector of the HUD.

2. Disconnect the HUD switch
3. Turn the ignition ON, with the engine OFF.

⇒	If the HUD does not turn OFF, replace the HUD.

4. Connect a test lamp between the ground circuit of the HUD switch and battery positive voltage.

⇒	If the test lamp does not illuminate, check the HUD switch ground circuit for an open or a high resistance.

⇒	If the HUD switch ground circuit test normal, replace the HUD switch.

5. Connect a test lamp between the HUD dimmer down switch signal circuit and battery positive voltage while pressing the HUD dimmer down switch.

⇒	If the test lamp does not illuminate, check the HUD dimmer down switch signal circuit for an open or a high resistance.

⇒	If the HUD dimmer down switch signal circuit tests normal, replace the HUD switch.

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.