Circuit/System Testing

WARNING: This page is about a different car, the 2013 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connectors at the following components.
- S48D multifunction switch 2 - instrument panel (with F45)
- S107 parking assist ON/OFF switch
Connect a test lamp between the control circuit terminal 3 and ground.
Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.
- If the test lamp is always OFF
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 is always ON
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 turns ON and OFF
Test or replace the appropriate switch.