Circuit/System Testing

WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the X2 harness connector at the K47 Rear Differential Clutch Control Module, ignition ON.
Test for less than 1 V between each control circuit terminal listed below and ground:
- Terminal 8
- Terminal 16
- If 1 V or greater
1. Ignition OFF, disconnect the X1 harness connector at the M32 Differential Clutch Pump.
2. Test for less than 1 V between each control circuit terminal listed below and ground:
  - Terminal 8
  - Terminal 16
  - If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V
Ignition OFF, connect the X2 harness connector at the K47 Rear Differential Clutch Control Module and disconnect the X1 harness connector at the M32 Differential Clutch Pump, ignition ON.
Verify a test lamp illuminates between each control circuit terminal listed below and ground:
- Terminal 1
- Terminal 2
- If the test lamp does not illuminate
1. Ignition OFF, disconnect the X2 harness connector at the K47 Rear Differential Clutch Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Test for less than 2 Ω on the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance on the circuit.
  - If less than 2 Ω, replace the K47 Rear Differential Clutch Control Module.
- If the test lamp illuminates
Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2.
Verify the test lamp increases in brightness when commanding the Pump Motor from 0% to 100% with a scan tool.
- If the test lamp does not increase in brightness
  Replace the K47 Rear Differential Clutch Control Module.
- If the test lamp increases in brightness
Test or replace the M32 Differential Clutch Pump.