Head Up Display (HUD) Inoperative

Head Up Display (HUD) Inoperative

Diagnostic Fault Information

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






Circuit/System Description

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 and engine speed information via discreet vehicle and engine speed signal circuits. The HUD also interfaces with the HUD switch via discreet circuits and the HUD switch inputs to the HUD is low. A press and hold of the dimming up switch greater than 500 msec 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 seperate Off switch. The HUD is turned off using the dimming down switch. A press and hold of the dimming down switch greater than 500 msec initiates a smooth decrease in the HUD intensity until the switch is released or the HUD is turned off.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the head-up display (HUD).
2. Test for less than 1.0 ohm of resistance between the HUD ground circuit and ground.

• If greater than 1.0 ohm, test the HUD ground circuit for an open/high resistance.

3. Verify a test lamp illuminates when connected between the HUD battery positive voltage circuit and ground.

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

4. Verify a test lamp illuminates when connected between the HUD dimming up switch signal circuit and B+ while pressing the HUD dimming up switch.

• If the test light does not illuminate, test the HUD dimming up switch signal circuit and the ground circuit for an open/high resistance. If the circuits test normal, replace the HUD switch.

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

Repair Instructions

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

* Refer to Programming and Relearning.Programming and Relearning
* Head Up Display Switch Replacement