Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, exterior lamps OFF, disconnect the appropriate component:
- B1AEA = E13LA Front Headlamp - Left
- B1AEB = E13RA Front Headlamp - Right
Verify a test lamp illuminates between ground circuit terminal 1 and B+.
- If the test lamp does not illuminate
1. Repair the open/high resistance on the ground circuit or ground connection.
- Go to next step: If the test lamp illuminates
Connect a test lamp between control circuit terminal 4 and ground, ignition ON/vehicle in service mode.
Verify the test lamp turns ON and OFF when commanding the appropriate Cornering Lamp ON and OFF with the scan tool.
- If the test lamp turns is always OFF
1. Test the appropriate circuit for an open/high resistance:
  - E4A Cornering Lamp - Left = Circuit 57
  - E4B Cornering Lamp - Right = Circuit 58
  - If an open/high resistance is found, repair the fault on the circuit
  - Go to next step: If an open/high resistance is not found
2. Test the appropriate circuit for a short to ground:
  - E4A Cornering Lamp - Left = Circuit 57
  - E4B Cornering Lamp - Right = Circuit 58
  - If a short to ground is found, repair the fault on the circuit
  - Go to next step: If a short to ground is not found
3. Replace the K219 Lighting Control Module.
- If the test lamp is always ON
1. Test the appropriate circuit for a short to voltage:
  - E4A Cornering Lamp - Left = Circuit 57
  - E4B Cornering Lamp - Right = Circuit 58
  - If a short to voltage is found, repair the fault.
  - Go to next step: If a short to voltage is not found.
2. Replace the K219 Lighting Control Module.
- Go to next step: If the test lamp turns ON and OFF
Replace the appropriate E13 Headlamp Assembly.