Circuit/System Verification

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Check for bulletins before proceeding.

Ignition ON.
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.
- If all parameters change
Verify every applicable scan tool Switch parameter changes when pressing the appropriate switch on the A34 HVAC Controls - Auxiliary.
- If any parameter does not change
  Replace the A34 HVAC Controls - Auxiliary.
- If all parameters change
Verify the front blower motor operates properly with the blower motor switch in each speed position.
- If the front blower motor does not operate in each speed position
  Refer to DTC B0193 .
- If the front blower motor operates properly in each speed position
Verify the rear blower motor operates properly with the blower motor switch in each speed position.
- If the rear blower motor does not operate properly in each speed position
  Refer to DTC B0208 .
- If the rear 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, B022A, B0233, B023A, B0408, B0418, B0428, or B3531 .
- If all HVAC doors move correctly
Install the appropriate ACR Air Conditioning Recharge Service Center. Ignition ON.
Verify the high side pressure reading on the Air Conditioning Service Center is within 10% of the scan tool A/C High Side Pressure Sensor parameter.
- If the reading is not within 10%
  Refer to DTC P0532 or P0533 .
- If the reading 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
- If the reading is between 269-2929 kPa (39-425 PSI)
Verify the scan tool parameters listed below are within 10% of ambient temperature.
- Lower Left Duct Air Temperature Sensor
- Upper Left Duct Air Temperature Sensor
- Lower Right Duct Air Temperature Sensor
- Upper Right Duct Air Temperature Sensor
- A/C Evaporator Temperature Sensor
- Lower Auxiliary Duct Air Temperature Sensor
- Upper Auxiliary Duct Air Temperature Sensor
- If not within 10% of ambient temperature
  Refer to DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933 .
- If within 10% of ambient temperature
Verify the 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 .
- 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 .
- If less than a 3°C (5°F) difference
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 .
- If within 10% of actual conditions
Engine ON, A/C system ON
Verify cool air flows from the ducts with the temperature control in the coldest position.
- If the air is not cool
1. Verify the Q2 A/C Compressor Clutch is engaged.
  - If the Q2 A/C Compressor Clutch is not engaged, refer to Air Conditioning Compressor Malfunction .
  - If the Q2 A/C Compressor Clutch is engaged, refer to Air Conditioning (A/C) System Performance Test , and DTC B393B .
- If the air is cool
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 .
- If the air is warm
All OK.