Circuit/System Testing
WARNING: This page is about a different car, the 2017 GMC Canyon and 2017 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
- 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 connectors at the components listed below.
- S48A Multifunction Switch - Instrument Panel
- S77 Transfer Case Shift Control Switch
- S79D Window Switch - Driver
- Ignition ON, place the dimmer switch in the HIGH position for high backlighting intensity.
- Verify a test lamp illuminates between each control circuit terminal listed below and ground.
- S48A Multifunction Switch - Instrument Panel terminal 2
- S77 Transfer Case Shift Control Switch terminal 4
- S79D Window Switch - Driver terminal 11
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module.
- 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
- 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 dimmer switch in the LOW position for low backlighting intensity.
- Verify a test lamp does not illuminate at FULL intensity between each control circuit terminal listed below and ground.
- S48A Multifunction Switch - Instrument Panel terminal 2
- S77 Transfer Case Shift Control Switch terminal 4
- S79D Window Switch - Driver terminal 11
- If the test lamp illuminates at full intensity
- Ignition OFF, disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
- 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 inoperative component.
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:
NOTE:
The test lamp in the following step will illuminate at LOW intensity. This is normal circuit operation and does not indicate a circuit malfunction.