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 B3621: Head-Up Display (HUD) Information Down SwitchDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
HUD Information Down Switch Signal Circuit | B3620 | -- | -- |
HUD Switch Ground Circuit | -- | -- | -- |
Circuit/System Description
The head-up display (HUD) information down switch is used to vertically adjust the HUD image on the windshield to accommodate various vehicle operator heights. The HUD monitors the information down switch signal circuit in order to adjust image positions. When the HUD information down 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 information down 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 switch.
- Test for less than 1.0 ohm of resistance between the HUD switch ground circuit terminal F and ground.
- Ignition ON, verify the scan tool Adjust Display Down Switch parameter is Inactive.
- Install a 3A fused jumper wire between the image down switch signal circuit terminal K and ground. Verify the scan tool Adjust Display Down Switch parameter is Active.
- If all circuits test normal, test or replace the HUD switch.
| ⇒ | If greater than 1.0 ohm, test the HUD switch ground circuit terminal F for an open/high resistance. |
| ⇒ | If not Inactive, test the image down switch signal circuit terminal K for a short to ground. If the circuit tests normal, replace the HUD. |
| ⇒ | If not Active, test the image down switch signal circuit terminal K 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.
