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, disconnect the X1 connector at the K56 Serial Data Gateway Module.
- Verify a test lamp illuminates between ground circuit terminal 4 X1 and B+
- If the test lamp does not illuminate
Repair the open/high resistance on circuit 2350 or the ground connection.
- Go to next step: If the test lamp illuminates
- If the test lamp does not illuminate
- Ignition ON.
- Verify a test lamp Illuminates between B+ circuit terminal 1 X1 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Test the B+ circuit 5940 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 or high resistance is not found
- 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
- Test the B+ circuit 5940 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
- Replace the K56 Serial Data Gateway Module.
- Go to next step: If the test lamp illuminates
- Verify voltage at B+ terminal 1 X1 is within 1 V of the C1 Battery voltage.
- If not the specified value
Repair the high resistance on circuit 5940.
- Go to next step: If the specified value
- If not the specified value
- Replace the K56 Serial Data Gateway Module.