Circuit/System Verification

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check for bulletins before proceeding.

Vehicle in Service Mode.
Verify every applicable scan tool switch parameter changes when pressing the appropriate switch on the A26 HVAC Controls.
- If any parameter does not change
  Replace the A26 HVAC Controls.
- Go to next step: If all parameters change
Verify that the blower motor operates properly with the blower motor switch in each speed position.
- If the blower motor does not operate in each speed position
  Refer to DTC B0193 .
- Go to next step: If the blower motor operates properly in each speed position.
Verify every HVAC door moves correctly when pressing the appropriate switch.
- If any HVAC door does not move correctly
  Refer to DTC B0223, B0228, B0233, B0408, B0413, B0418, B0423, B1395, or B374A .
- Go to next step: If all HVAC doors move correctly
Install the appropriate Air Conditioning Service Center, Vehicle in Service Mode.
Verify the high side pressure on the gauge is within 10% of the scan tool A/C High Side Pressure Sensor parameter.
- If the A/C High Side Pressure Sensor parameter is not within 10%
  Refer to DTC P0532 or P0533 .
- Go to next step: If the A/C High Side Pressure Sensor parameter is within 10%
Verify the A/C High Side Pressure Sensor parameter is between 269-2929 kPa (39-425 PSI).
- If the reading is not between 269-2929 kPa (39-425 PSI)
  Refer to Air Conditioning (A/C) System Performance Test
- Go to next step: If the reading is between 269-2929 kPa (39-425 PSI)
Verify the low side pressure on the gauge is within 10% of the scan tool A/C Low Side Pressure Sensor parameter.
- If the A/C Low Side Pressure Sensor parameter is not within 10%
  Refer to DTC P151C or P2516-P2518 .
- Go to next step: If the A/C Low Side Pressure Sensor parameter is within 10%
Verify the A/C Evaporator Temperature Sensor parameter is within 10% of actual conditions.
- If not within 10% of actual conditions
  Refer to DTC B3933 .
- Go to next step: If within 10% of actual conditions
Verify the scan tool parameters listed below are within 10% of actual conditions.
- Passenger Compartment Humidity
- Passenger Compartment Humidity Sensor Temperature
- Passenger Compartment Windshield Temperature
- If not within 10% of actual conditions
  Refer to DTC B018A, B048C, B048F, or B1395 .
- Go to next step: If within 10% of actual conditions
Verify the scan tool Sunload parameter changes while covering the B10B Ambient Light/Sunload Sensor with a shop towel or other suitable item.
- If the Sunload parameter does not change
  Refer to DTC B0163 or B0183 .
- Go to next step: If the Sunload parameter changes
Verify the actual inside air temperature, using a thermometer, is less than 3°C (5°F) difference from the scan tool Inside Passenger Compartment Air Temp. Sensor parameter.
- If greater than a 3°C (5°F) difference
  Refer to DTC B0163 or B0183 .
- Go to next step: If less than a 3°C (5°F) difference
Vehicle ON and A/C ON.
Verify cool air flows from the ducts with the temperature control in the coldest position.
- If the air is not cool
  Refer to Air Conditioning (A/C) System Performance Test .
- Go to next step: If the air is cool
Verify the G36 Auxiliary Heater Coolant Pump turns On and Off when commanded with a scan tool.
- If the G36 Auxiliary Heater Coolant Pump does not turn On and Off
  Refer to DTC B269A, B269C, or B269D .
- Go to next step: If the G36 Auxiliary Heater Coolant Pump turns On and Off
Verify the E40 Electrical Auxiliary Heater is operating properly.
- If the E40 Electrical Auxiliary Heater is not operating properly
  Refer to DTC B048D
- Go to next step: If the E40 Electrical Auxiliary Heater is operating properly.
Verify warm air flows from the ducts with the temperature control in the warmest position.
- If the air is not warm
  Refer to Heating Performance Diagnostic .
- Go to next step: If the air is warm
All OK.