Circuit/System Testing

NOTE:

Each component with backlighting may need to be disconnected to isolate a short to voltage or short to ground. Use the schematics to identify the following:

Backlighting components the vehicle is equipped with
Each component's control and ground circuit terminals
Component locations on the backlighting control circuit

Ignition OFF, disconnect the harness connector at the S48A Multifunction Switch - Instrument Panel.
Ignition ON, place the instrument panel dimmer switch in the HIGH position for high backlighting intensity.
Verify a test lamp illuminates between the control circuit terminal 13 and ground.
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K9 Body Control Module.
- If the test lamp illuminates
Place the instrument panel dimmer switch in the LOW position for low backlighting intensity.
Verify a test lamp does not illuminate at FULL intensity between the control circuit terminal 13 and ground.
- If the test lamp illuminates at full intensity
1. Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit terminal and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the K9 Body Control Module.
- If the test lamp does not illuminate at full intensity
Test or replace the S48A Multifunction Switch - Instrument Panel.