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 B3634: Head-Up Display (HUD) Dimming Up Switch Short to GroundDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
HUD Dimming Up Switch Signal Circuit | B3634 | -- | -- |
HUD Switch Ground Circuit | -- | -- | -- |
Circuit/System Description
The head-up display (HUD) dimming up switch is a momentary contact switch that adjusts the HUD display brightness. The HUD dimmer up switch controls the intensity of the brightness. The HUD senses when the dimming up switch is active and adjusts the display brightness until the desired intensity is attained. When the HUD dimming up switch is pressed and the ignition is in the RUN position, the dimming up switch signal to the HUD is low. A press and hold of the dimming up switch greater than 1 sec initiates a smooth increase in the HUD intensity until the switch is released or maximum intensity is achieved.
Conditions for Running the DTC
The ignition is in RUN.
Conditions for Setting the DTC
The HUD detects that the HUD dimming 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
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the HUD.
- Verify a test lamp does not illuminate when connected between the HUD dimming up switch signal circuit terminal 11 and B+.
- If all circuits test normal, test or replace the HUD switch.
| ⇒ | If the test light illuminates, test the HUD dimming up switch signal circuit terminal 11 for a short to ground. If the circuit tests normal, replace the HUD. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
