Circuit/System Testing

WARNING: This page is about a different car, the 2012 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, exterior lamps OFF, disconnect the harness connector at the E6 center high mounted stop lamp.
Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- If 5 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 5 Ω
Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.
Verify the test lamp turns ON and OFF when commanding the Center Brake Lamp ON and OFF with a scan tool.
- If the test lamp is always OFF
1. Ignition OFF, disconnect the X4 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 X4 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 E6 center high mounted stop lamp.