Circuit/System Verification

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. 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.
- Go to next step: 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 properly in each speed position
  Refer to DTC B0193 .
- Go to next step: If the blower motor operates properly in each speed position
Verify the Air Quality Sensor parameter changes while introducing hydrocarbons from a suitable source into the vicinity of the B108 Air Quality Sensor.
- If the Air Quality Sensor parameter does not change
  Refer to DTC B3843 .
- Go to next step: If the Air Quality Sensor parameter changes
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, B022A, B0233, B023A, B0408, or B0418 .
- Go to next step: If all HVAC doors move
Install the J43600 ACR Air Conditioning 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 P0532 or P0533 .
- Go to next step: 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
- Go to next step: 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
- If not within 10% of ambient temperature
  Refer to DTC B0173, B0178, B0509, B0514 or B3933 .
- Go to next step: If within 10% of ambient temperature
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 .
- Go to next step: 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 .
- Go to next step: If the air is warm
Engine OFF, ignition ON.
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, B0183, or B1405 .
- 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, B0183, or B1405 .
- Go to next step: If less than a 3°C (5°F) difference
Verify the G8 Coolant Pump - Auxiliary turns On and Off when commanded with a scan tool.
- If the G8 Coolant Pump - Auxiliary does not turn On and Off
  Refer to DTC B269A, B269C, or B269D .
- Go to next step: If the G8 Coolant Pump - Auxiliary does turn On and Off
All OK.