Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the HUD switch.
- Test for less than 5.0 ohms between the HUD switch ground circuit terminal F and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Adjust Display Down Switch parameter is Inactive.
- If not Inactive, test the signal circuit terminal K for a short to ground. If the circuit tests normal, replace the HUD.
- Install a 3A fused jumper wire between the signal circuit terminal K and ground. Verify the scan tool Adjust Display Down 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.
- If all circuits test normal, test or replace the HUD switch.