Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B3744: Head-Up Display (HUD) Mode Switch Signal Circuit Short to GroundDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
HUD Battery+ | 1 | 1 | -- |
HUD Ground | -- | 1 | 1 |
HUD Page Switch Signal | B3619 | 1 | 1 |
HUD Up Switch Signal | B3620 | 1 | 1 |
HUD Down Switch Signal | B3621 | 1 | 1 |
HUD Dimming Up switch Signal | B3634 | 1 | 1 |
HUD Dimming Down Switch Signal | B3659 | 1 | 1 |
HUD Mode Switch Signal | B3744 | 1 | 1 |
HUD Switch Ground | -- | 1 | 1 |
1. Head- up Display (HUD) Malfunction. | |||
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
Connector End View Reference
Description and Operation
Head Up Display (HUD) Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References 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
- Ignition OFF, disconnect the harness connector at the HUD switch.
- Test for less than 5 ohms between the ground circuit terminal F and ground.
- Ignition ON, verify the scan tool Mode Switch parameter is Inactive.
- Install a 3A fused jumper wire between the signal circuit terminal G and ground. Verify the scan tool mode switch parameter is Active.
- If all circuits test normal, test or replace the HUD switch.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not Inactive, test the signal circuit terminal G for a short to ground. If the circuit tests normal, replace the HUD. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
