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 power source to the HUD system. The HUD system can only be enabled when the ignition is active and in RUN position. The HUD receives vehicle information to be displayed via class 2 serial data circuit. The HUD system also receives vehicle information via discreet vehicle speed circuits. The HUD interfaces with the HUD switch via discreet circuits and the HUD switch inputs to the HUD is low. The dim select switch initiates a smooth increase in the HUD display intensity until the switch is released or maximum intensity is achieved. The HUD does not have a separate Off switch. The HUD is turned off using the dim select switch. The dim select switch initiates a smooth decrease in the HUD intensity until the switch is released or the HUD is turned off.

Schematic Reference

Connector End View Reference

Description and Operation

Head Up Display (HUD) Description and Operation

Electrical Information Reference

Scan Tool Reference

Scan Tool Data List

1. Ignition OFF, disconnect the harness connector at the dimming/head-up display (HUD) switch.
2. Test for less than 1 ohm of resistance between the HUD switch ground circuit terminal 1 and ground.

⇒	If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Dim Select Switch parameter is Inactive.

⇒	If not Inactive, test the dimmer switch down signal circuit terminal 3 or dimmer switch up signal terminal 2 for a short to ground. If the circuits test normal, replace the HUD.

4. Install a 3A fused jumper wire between the dimmer switch up signal circuit terminal 2 or dimmer switch down signal terminal 3 and the ground circuit terminal 1. Verify the scan tool Dim Up Switch and Dim Down Switch parameter is Active.

⇒	If any is not Active, test the appropriate dimmer switch signal circuit for a short to voltage or an open/high resistance. If the circuit(s) tests normal, replace the HUD.

5. Ignition OFF, disconnect the harness connector at the HUD.
6. Test for less than 1 ohm of resistance between the HUD ground circuit terminal 10 and ground.

⇒	If greater than 1 ohm, test the ground circuit for an open/high resistance.

7. Ignition ON, verify a test lamp illuminates when connected between the battery positive voltage circuit terminal 1 and the ground circuit terminal 10.

⇒	If the test light does not illuminate, test the HUD battery positive voltage circuit for an open/high resistance.

8. If all circuits test normal, test or replace the HUD.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.