Head Up Display (HUD) Always On

Head Up Display (HUD) Always On

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



Diagnostic Fault Information






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 on 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 for display via the serial data circuit. The HUD system also receives vehicle and engine speed information via discreet vehicle and engine speed signal circuits. The HUD 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 1 second 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 dimming down switch. A press and hold of the dimming down switch greater than 1 second initiates a smooth decrease in the HUD intensity until the switch is released or the HUD is turned OFF.


Reference Information
Schematic Reference

Head Up Display Schematics (Head Up Display Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Head Up Display (HUD) Description and Operation (Head Up Display (HUD) Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the HUD.
2. Verify a test lamp illuminates when connected between the HUD dim down switch signal circuit terminal 12 and B+ while pressing the HUD dimming down switch.

• If the test light does not illuminate, test the signal circuit and the ground circuit terminal 6 for an open/high resistance. If the circuit(s) test normal, replace the HUD switch.

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



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control Module References (Programming and Relearning) for the HUD replacement, setup and programming
* Head Up Display Switch Replacement (Head Up Display Switch Replacement)