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.
- Ignition OFF, disconnect the KR50 Headlamp Relay, ignition ON
- Verify a test lamp illuminates between the B+ circuit terminal 86 and ground.
- If the test lamp does not illuminate
Replace the X50A Fuse Block - Underhood.
- Go to next step: If the test lamp illuminates
- If the test lamp does not illuminate
- Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
- If the test lamp does not illuminate
Replace the X50A Fuse Block - Underhood.
- Go to next step: If the test lamp illuminates
- If the test lamp does not illuminate
- Connect a test lamp between the control circuit terminal 85 and B+, ignition ON.
- Verify the test lamp turns ON and OFF when commanding the Low Beam Lamps ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X5 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.
- Go to next step: If less than 1 V
- Ignition OFF.
- 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 X5 harness connector at the K9 Body Control Module.
- Test for infinite resistance between the control circuit terminal 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 turns ON and OFF
- Ignition OFF, exterior lamps OFF, connect the KR50 Headlamp Relay.
- Disconnect the harness connector at the appropriate E13 Headlamp Assembly.
- Test for less than 5 Ω between the ground circuit terminal 10 and ground.
- If 5 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 5 Ω
- Connect a test lamp between the control circuit terminal 3 and ground, ignition ON.
- Verify the test lamp turns ON and OFF when commanding the Low Beam Lamps ON and OFF with a scan tool.
- If the test lamp is always OFF
- Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
- 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 KR50 Headlamp Relay.
- If the test lamp is always ON
- Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood, 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 KR50 Headlamp Relay.
- Go to next step: If the test lamp turns ON and OFF
- Ignition OFF, replace the appropriate T7 Headlamp Ballast.
- Ignition ON, verify the appropriate low beam headlamp illuminates when commanded ON with the headlamp switch.
- If the low beam headlamp does not illuminate
Replace the E13 Headlamp Assembly.
- Go to next step: If the low beam headlamp illuminates
- If the low beam headlamp does not illuminate
- All OK.