Circuit/System Testing
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
Dome Lamp Switch Malfunction
- Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the E37F Dome/Reading Lamps - Front. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 15 Ω between the ground circuit terminal 6 and ground.
- If 15 Ω or greater
- Ignition OFF.
- 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.
- Go to next step: If less than 15 Ω
- Ignition ON.
- Verify the scan tool Interior/Courtesy Lighting Master Switch parameter is Door.
- If Cancel
- Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the signal circuit terminal 4 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K9 Body Control Module.
- If On
- Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the signal circuit terminal 5 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If Door
- Install a 3 A fused jumper wire between the signal circuit terminal 4 and ground.
- Verify the scan tool Interior/Courtesy Lighting Master Switch parameter is Cancel.
- If not Cancel
- Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 4 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Test for less than 2 Ω in the signal 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.
- Go to next step: If Cancel
- Install a 3 A fused jumper wire between the signal circuit terminal 5 and ground.
- Verify the scan tool Interior/Courtesy Lighting Master Switch parameter is On.
- If not On
- Ignition OFF, disconnect the X7 harness connector at the K9 Body Control Module, ignition ON.
- Test for less than 1 V between the signal circuit terminal 5 and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Test for less than 2 Ω in the signal 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.
- Go to next step: If On
- Test or replace the E37F Dome/Reading Lamps - Front.
Dome Lamp Malfunction
- Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
- Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, disconnect the harness connector at the X51A Fuse Block - Instrument Panel.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, disconnect the harness connector at the X51A Fuse Block - Instrument Panel.
- Test for infinite resistance between the B+ circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If the test lamp illuminates
- Ignition OFF, connect the X5 harness connector at the K9 Body Control Module.
- Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the E37F Dome/Reading Lamps - Front. It may take up to 2 min for all vehicle systems to power down.
- Test for less than 15 Ω between the ground circuit terminal 6 and ground.
- If 15 Ω or greater
- Ignition OFF.
- 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.
- Go to next step: If less than 15 Ω
- Connect a test lamp between the control circuit terminal 2 and ground.
- Verify the test lamp turns ON and OFF when commanding the Courtesy Lamps ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X7 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.
- Go to next step: 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 is always ON
- Ignition OFF, disconnect the X7 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.
- Go to next step: If the test lamp turns ON and OFF
- Test or replace the inoperative E37F Dome/Reading Lamps - Front.