B3620

DTC B3620

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.

DTC Descriptor
DTC B3620
- Head-Up Display (HUD) Image Up Switch Signal Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The head-up display (HUD) image down or image up switch are used to vertically adjust the HUD image on the windshield to accommodate various vehicle operator heights. The HUD monitors the image down or image up switch signal circuit in order to adjust image positions. When the HUD image down or image up switch is depressed and the ignition is in the RUN position, the switch signal to the HUD is low.

Conditions for Running the DTC

The ignition is in RUN.

Conditions for Setting the DTC

The HUD detects that the HUD image up switch signal circuit is low for greater than 60 seconds.

Action Taken When the DTC Sets

The HUD ignores the malfunctioning switch circuit.

Conditions for Clearing the DTC

* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.

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) for scan tool information.

Circuit/System Verification

Ignition ON, verify that when the HUD image up switch is pressed and released the HUD scan tool Adjust Display Up Switch parameter toggles between Active and Inactive.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the HUD switch.
2. Test for less than 5.0 ohm between the low reference circuit terminal 1 and ground.

• If greater than the specified range, test the low reference circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Adjust Display Up Switch parameter is Inactive.

• If not Inactive, 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 switch signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Adjust Display Up Switch parameter is Active.

• If 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 circuits test normal, test or replace the HUD switch.

Repair Instructions

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

* Control Module References (Programming and Relearning)
* Head Up Display Switch Replacement (Head Up Display Switch Replacement)