Circuit/System Verification

WARNING: This page is about a different car, the 2017 Cadillac ATS. 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 A20 Radio/ HVAC Controls.
- If any parameter does not change
  Replace the A20 Radio/ HVAC Controls.
- If all parameters change
Verify 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 .
- If the blower motor operates properly in each speed position
Verify the HVAC doors listed below move when pressing the appropriate switch.
- Driver Temperature
- Passenger Temperature
- Mode
- Recirculation
- If any HVAC door does not move
  Refer to DTC B0223, B0228, B0233, B0408, B0413, B0418, B0423, B1395, or B374A .
- If all HVAC doors move
Install the appropriate ACR Air Conditioning Recharge Service Center.
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 P0531, 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 (R-134a)Air Conditioning (A/C) System Performance Test (R-1234yf)
- 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
- Lower Right Duct Air Temperature Sensor
- A/C Evaporator Temperature Sensor
- If not within 10% of ambient temperature
  Refer to DTC B0178 or B0514 .
- If within 10% of ambient temperature
Verify theA/C Evaporator Temperature Sensor scan tool parameter is within 10% of ambient temperature.
- If not within 10% of ambient temperature
  Refer to DTC B3933 .
- If within 10% of ambient temperature
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 (R-134a)Air Conditioning (A/C) System Performance Test (R-1234yf) , 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
Engine OFF, ignition ON.
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 (Without UE1) .
- 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 B0183 (Without UE1) .
- If less than a 3°C (5°F) difference
All OK.