Circuit/System Testing

2013 Buick Regal Turbo Premium, Standard TransSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2012 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the Q46 A/C compressor solenoid valve. It may take up to 2 minutes for all vehicle systems to power down
  2. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground

      If the test lamp does not illuminate 

    1. Test for infinite resistance between the B+ circuit and ground
      • If less than infinite resistance, repair the short to ground on the circuit
      • If infinite resistance
    2. Test for less than 2Ω in the B+ circuit end to end
      • If 2Ω or greater, repair the open/high resistance in the circuit
      • If less than 2Ω, replace the K33 HVAC control module

    If the test lamp illuminates 

  3. Ignition ON, connect a test lamp between the control circuit terminal 1 and the B+ circuit terminal 2
  4. Verify the test lamp turns ON and OFF when commanding the A/C Compressor Refrigerant Solenoid Valve ON and OFF with a scan tool

      If the test lamp is always OFF 

    1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module, ignition ON
    2. Test for less than 1 V between the control circuit and ground
      • If 1 V or greater, repair the short to voltage on the circuit
      • If less than 1 V
    3. Ignition OFF
    4. Test for less than 2Ω in the control circuit end to end
      • If 2Ω or greater, repair the open/high resistance in the circuit
      • If less than 2Ω, replace the K33 HVAC control module.
    5. If the test lamp is always ON 

    • Ignition OFF, disconnect the harness connector at the K33 HVAC control module
    • 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, replace the K33 HVAC control module

    If the test lamp is always OFF  

  5. Test or replace the Q46 A/C compressor solenoid valve
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.