Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, 2019 Buick Regal, and 2018 Buick Regal TourX. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the S48E Multifunction Switch.
Test for less than 10 Ω between the ground circuit terminal 1 and ground.
- If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω at the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 10 Ω
Ignition ON, verify with a scan tool the Engine control Module Stop/Start Mode parameter is No.
- If the parameter is YES
1. Ignition OFF, disconnect the harness connector X1 at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground at the circuit.
  - If infinite resistance, replace the K9 Body Control Module.
- Go to next step: If the parameter is NO
Install a 3 A fused jumper wire between the signal circuit terminal 12 X1 and ground. Verify the ECM scan tool Stop/Start Mode parameter is Yes.
- If the parameter is NO
1. Ignition OFF.
2. Disconnect the harness connector X1 at the K9 Body Control Module.
3. Test for less than 1 V the control circuit and ground.
  - If greater than 1 V, repair the short to voltage.
  - If less than 1 V, replace the K9 Body Control Module.
- Go to next step: If the parameter is YES
Replace the S48E Multifunction Switch.