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 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 the serial data circuit. The HUD system also receives vehicle speed information via discreet vehicle speed signal circuit. The HUD interfaces with the HUD switch via discreet circuits and the HUD switch inputs to the HUD is low. The dimmer/HUD up 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 dimmer/HUD down switch. The dimmer/HUD down switch 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 dimmer/head-up display (HUD) switch.
2. Test for less than 1 ohm of resistance between the 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 in the IPC Data List is Inactive.

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

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

• If any is not Active, test the appropriate switch signal circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the HUD.

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



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)