Head Up Display (HUD) Malfunction
Head Up Display (HUD) Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The head-up display (HUD) is a display system that optically projects vehicle information onto the windshield. The HUD has an electric tilt adjust that is controlled by the up and down switches. Operating these switches directs the motor to move the HUD image up or down on the windshield. The HUD is equipped with a page switch that scrolls through multiple messages present on the HUD. The HUD is also equipped with automatic dimming. Dimming is controlled by a HUD dimmer switch. All three switches control the HUD by grounding the HUD switch input signals. The dimmer switch uses a variable resistor to control the HUD intensity where the lower the resistance, the brighter the HUD display.
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 (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Programming and Relearning (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, verify that the HUD image is displayed on the windshield.
• If the HUD image is not displayed, refer to HUD Inoperative.
2. Ignition ON, verify that when the HUD switches are pressed and released the HUD scan tool parameters toggle between Active and Inactive.
• If the parameters do not toggle between Active and Inactive, refer to HUD Switch Malfunction.
Circuit/System Testing
HUD Inoperative
1. Ignition OFF, disconnect the harness connector at the HUD switch.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HUD.
3. Verify the scan tool Display Dimming parameter is greater than 98 percent.
• If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the HUD.
4. Install a 3A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 3. Verify the scan tool Display Dimming parameter is less than 2 percent.
• If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the HUD.
5. If all circuits test normal, test or replace the HUD switch.
HUD Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the HUD switch assembly.
2. Ignition OFF, test for less than 5 ohms between the low reference terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
3. Ignition ON, verify that all of the scan tool HUD Switch parameters are Inactive.
• If any is not Inactive, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the HUD.
4. Ignition ON, install a 3-amp fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool HUD Switch parameters are Active.
• If any are not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HUD.
5. If all the circuits test normal, test or replace the HUD switch assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Head Up Display Switch Replacement (Acadia) (Head Up Display Switch Replacement)
* Control Module References (Programming and Relearning) for HUD replacement, setup, and programming