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.

NOTE:

Each component may need to be disconnected to isolate a short to voltage, short to ground, or an open/high resistance. Use the schematics to identify the following:

Courtesy lamps the vehicle is equipped with
Each component's control and ground circuit terminals
Component locations on control circuit 4782

Set the S36 Dimmer Switch to full intensity.
Ignition OFF, disconnect the X1 connector at the K9 Body Control Module, ignition ON.
Verify the accent/courtesy lamps are not illuminated:
- E88 Front Floor Console Bin Lamp
- E1AC Accent Lamp - Center Console Cupholder
- If an accent/courtesy lamp is illuminated
  Repair the short to voltage on circuit 4782.
- Go to next step: If all accent/courtesy lamps are not illuminated
Connect a 3 A fused jumper wire between B+ and circuit terminal 1 at the X1 connector.
Verify the accent/courtesy lamps are illuminated.
- If an accent/courtesy lamp is not illuminated and the jumper fuse is OK.
1. Test circuit 1450 for an open/high resistance:
  - If an open/high resistance is found, repair the fault on the circuit or ground connection.
  - Go to next step: If an open/high resistance is not found.
2. Test circuit 4782 for an open/high resistance.
  - 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
3. Replace the appropriate accent/courtesy lamp.
- If the accent/courtesy lamp is not illuminated and the jumper fuse is open
1. Test circuit 4782 for a short to ground.
  - 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
2. Replace the appropriate accent/courtesy lamp.
- Go to next step: If the accent/courtesy lamps are illuminated
Replace the K9 Body Control Module.