Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the dimmer/head-up display (HUD) switch.
- Test for less than 1 ohm of resistance between the ground circuit terminal 1 and ground.
- If greater than 1 ohm, test the ground circuit for an open/high resistance.
- Ignition ON, verify the scan tool Dim Select Switch parameter in the IPC Data List is Inactive.
- If not Inactive, test the dimmer/HUD up switch signal circuit terminal 2 or the dimmer/HUD down switch signal circuit terminal 3 for a short to ground. If the circuits test normal, replace the HUD.
- Install a 3A fused jumper wire between the dimmer/HUD up switch signal circuit terminal 2 or the dimmer/HUD down switch signal circuit terminal 3 and the ground circuit terminal 1. Verify the scan tool Dim Up Switch/Dim Down Switch parameter in the IPC Data List is Active.
- If any is not Active, test the appropriate switch signal circuit for a short to voltage or an open/high resistance. If the circuits test normal, replace the HUD.
- If all circuits test normal, test or replace the dimmer/HUD switch.