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, all accessories Off.
Remove the KR76 Accessory Time Delay Cutoff Relay.
Verify a test lamp illuminates between ground terminal 85 and B+.
- If the test lamp does not illuminate
1. Test for open/high resistance in ground circuit 1350.
  - If open/high resistance is found, repair the circuit or ground connection.
  - Go to next step: If open/high resistance is not found
2. Replace the X51A Fuse Block - Instrument Panel.
- Go to next step: If the test lamp illuminates
Ignition ON, Run Mode,
Verify a test lamp illuminates between control circuit terminal 86 and ground.
- If the test lamp does not illuminate
1. Ignition OFF.
2. Test for a short to ground in control circuit 4083.
  - If a short is found, repair the circuit.
  - Go to next step: if a short to ground is not found
1. Test for open/high resistance in control circuit 4083.
  - If open/high resistance is found, repair the circuit.
  - Go to next step: If open/high resistance is not found.
2. Replace the K9 Body Control Module.
- Go to next step: If the test lamp turns On
Open the drivers door latch.
Cycle the Ignition between, Run Mode and Off Mode.
Verify a test lamp turns On and Off between control circuit terminal 86 and ground.
- If the test lamp is always On
1. Ignition ON, Run Mode.
2. Test for a short to voltage in control circuit 4083.
  - If a short to voltage is found, repair the circuit.
  - Go to next step: If a short to voltage is not found.
3. Replace the K9 Body Control Module.
- Go to next step: If the test lamp turns On and Off
Test or replace the KR76 Accessory Time Delay Cutoff Relay.