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Home >> Buick >> 2014 >> Verano Base >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC System - Manual >> Diagnostic Information and Procedures >> DTC B0223, B0233, B023A or B0408: Recirculate Position Command/Air Flow Control Circuit/HVAC Actuators/Main Temperature Control Circuit >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate door actuator, ignition ON.
  2. Connect a test lamp between the B+ circuit terminal 2 and ground.
  3. Verify the test lamp turns ON and OFF repeatedly when commanding the actuator ON but not 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.
    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 in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K33 HVAC control module.
    • If the test lamp is always ON 
    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, replace the K33 HVAC control module.
    • If the test lamp turns ON and OFF 
  4. Connect a test lamp between each actuator harness connector terminal listed below one at a time and B+.
    • Control Circuit - terminal 1
    • Control Circuit - terminal 3
    • Control Circuit - terminal 4
    • Control Circuit - terminal 6
  5. Verify the test lamp turns ON and OFF repeatedly when commanding the actuator ON but not 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 less 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 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K33 HVAC control module.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the harness connector at the K33 HVAC 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, replace the K33 HVAC control module.
    • If the test lamp turns ON and OFF 
  6. Replace the appropriate HVAC door actuator.
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