Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT5. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/vehicle OFF, disconnect the harness connector at the M81 Sunroof Sunshade Motor.
Verify a test lamp illuminates between low reference circuit terminal and B+.
- If the test lamp does not illuminate
1. Test the low reference circuit 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.
2. Replace the K61 Sunroof Control Module.
- Go to next step: If the test lamp illuminates
Install a test lamp between control circuit 3781 and control circuit 3782 at the M81 Sunroof Sunshade harness connector.
Verify the test lamp momentarily turns On and Off when pressing the sunshade switch Open and Closed.
- If the test lamp is always Off
1. Disconnect harness connector at K61 Sunroof Control module.
2. Test circuits listed below for a short to ground.
  - Circuit 3781
  - Circuit 3782
  - 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. Disconnect harness connector at K61 Sunroof Control module.
4. Test circuits listed below for an open/high resistance.
  - Circuit 3781
  - Circuit 3782
  - 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.
5. Replace the K61 Sunroof Control Module.
- If the test lamp is always On
1. Ignition/vehicle OFF, disconnect the harness connector at the K61 Sunroof Control Module
2. Test for less than 1 V between control circuits listed below and ground.
  - Circuit 3781
  - Circuit 3782
  - If a short to voltage is found, repair the fault on the circuit.
  - Go to next step: If a short to voltage is not found.
3. Replace the K61 Sunroof Control Module.
- Go to next step: If the test lamp turns On and Off
Replace the M81 Sunroof Sunshade Motor