B3620

DTC B3620

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.

DTC Descriptor

DTC B3620

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Head-Up Display (HUD) Up Switch Signal Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The head-up display (HUD) image up switch is used to vertically adjust the HUD image on the windshield to accommodate various vehicle operator heights. The HUD monitors the image up switch signal circuit in order to adjust image positions. When the HUD 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 5 Bow Lowered Switch (CM7)

Description and Operation

Head-Up Display Description and Operation 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

Control Module References Control Module References 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 ohms between the ground circuit terminal F and ground.

• If greater than the specified range, test the ground 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 J 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 J and ground. 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 Control Module References

* Head Up Display Switch Replacement Head Up Display Switch Replacement