B3744

DTC B3744

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 B3744
- Head-Up Display (HUD) Mode Switch Signal Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

The head-up display (HUD) mode switch is a momentary contact switch. The HUD monitors the mode switch signal circuit in order to perform the mode switch functions. The HUD mode switch allows the driver to select a mode format to be displayed. Each press of the mode switch displays the next available format and overriding the current mode displayed. The HUD has 3 modes available through the mode switch: Mode 1 - Street Mode, Mode 2 - Track Mode 2 and Mode 3 - Track Mode 2. Vehicle information and warnings can also be acknowledged or removed by pressing the mode switch. When the HUD mode switch is pressed and the ignition is in the RUN position, the mode 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 mode 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 End Views By Name)
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 (Programming and Relearning) for scan tool information.

Circuit/System Verification

Ignition ON, verify that when the HUD mode switch is pressed and released the HUD scan tool Mode 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 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 Mode Switch parameter is Inactive.

• If not Inactive, test the signal circuit terminal G 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 G and ground. Verify the scan tool mode 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)