Circuit/System Testing

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the harness connector at the Q46 A/C Compressor Solenoid Valve. Connect a test light between terminals 1 and 2 of the harness connector. Ignition ON.
Verify the test light turns on and off when commanding the Q46 A/C Compressor Solenoid Valve ON and OFF with the scan tool.
- If the test light does not turn ON and OFF
1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module, ignition ON.
2. Test for less than 1 V between ground and each control circuit terminal listed below:
  - terminal 10
  - terminal 11
  - If 1 V or greater, repair the short to voltage on the circuit.
  - Go to next step: If less than 1 V
3. Ignition OFF.
4. Test for infinite resistance between ground and each control circuit terminal listed below:
  - terminal 10
  - terminal 11
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
5. Test for less than 2 Ω in each of the control circuits end to end listed below:
  - Q46 A/C Compressor Solenoid Valve terminal 1 and K33 HVAC Control Module terminal 10
  - Q46 A/C Compressor Solenoid Valve terminal 2 and K33 HVAC Control Module terminal 11
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - Go to next step: If less than 2 Ω, replace the K33 HVAC Control Module.
- Go to next step: If the test light turns ON and OFF
Test the Q46 A/C Compressor Solenoid Valve or replace the G1 A/C Compressor.