Diagnostic Fault Information
Important: Always perform the Diagnostic System Check - Vehicle
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
HUD Battery Voltage Circuit | -- | 2 | -- | -- |
HUD Ground Circuit | -- | 2 | -- | -- |
HUD Switch Ground Circuit | -- | 1 | -- | -- |
1. Head Up Display (HUD) Always On | ||||
2. Head Up Display HUD Inoperative | ||||
Circuit/System Description
The head up display (HUD) is a secondary display system capable of reflecting important vehicle information onto the windshield. The vehicle information is displayed using virtual imaging and is reflected off the windshield in front of the driver. Battery positive voltage is the main power source for the HUD system. However, the HUD system can only be enabled when the ignition is active and in the RUN position. The HUD system receives all vehicle information to be displayed via the class 2 serial data circuit. The HUD system interfaces with the HUD switch via discreet circuits. The HUD switch is a normally open switch and ground is provided from within the HUD switch when any switch press occurs.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- With the ignition ON, turn the HUD dimmer up switch to the full intensity.
- With the ignition OFF, disconnect the HUD.
- Connect a test lamp between the HUD battery positive voltage and a good ground.
- Turn the ignition ON, with the engine OFF.
- Connect a test lamp between the HUD battery positive voltage and the HUD ground circuit.
- With the ignition turned OFF, disconnect the HUD switch.
- Connect a test lamp between the HUD switch ground circuit and the HUD battery positive voltage circuit.
- Turn the ignition ON, with the engine OFF.
- Connect a test lamp between the HUD dimmer up switch signal circuit and the HUD battery positive voltage circuit while the HUD dimmer up switch is active.
- Turn the ignition ON, with the engine OFF.
| ⇒ | If the HUD display turns on normally, check for intermittent and poor connection at the harness connector of the HUD. |
| ⇒ | If the test lamp does not illuminate, check the HUD battery positive voltage for an open or a high resistance. |
| ⇒ | If the test lamp does not illuminate, check the HUD ground circuit for an open or a high resistance. |
| ⇒ | If the test lamp does not illuminate, check the HUD switch ground circuit for an open or a high resistance. |
| ⇒ | If the test lamp illuminates, replace the HUD. |
| ⇒ | If the test lamp does not illuminate, test the HUD dimmer up switch signal circuit for an open or a high resistance. |
| ⇒ | If the HUD dimmer up switch signal circuit tests normal, replace the HUD switch. |
Repair Instructions
Important: Always perform the CELL LINK 143214 after completing the diagnostic procedure.
