Circuit/System Verification
WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Check for bulletins before proceeding.
- Ignition ON/ Vehicle in Service Mode.
- Verify no DTCs are set
- If any DTCs are set
- Go to next step: If no DTCs are set
- 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 Blower Motor Malfunction .
- Go to next step: If the blower motor operates properly in each speed position
- If the blower motor does not operate in each speed position
- Verify every HVAC door moves correctly when operating the appropriate control.
- If any HVAC door does not move correctly
- Inspect the HVAC door for any mechanical issues that may limit or prevent the air control door from moving smoothly or moving through its full range of travel.
- If any mechanical issues are found, repair or replace as necessary.
- Go to next step: If no mechanical issues are found
- Replace the malfunctioning actuator.
- Go to next step: If all HVAC doors move correctly
- Verify the A/C Evaporator Temperature Sensor parameter is within 10% of ambient temperature.
- If not within 10% of ambient temperature
Refer to DTC P0535, P0537, P0538, or P153B (LF4) , or DTC P0535, P0537, P0538, or P153B (L3B, LSY) .
- Go to next step: If within 10% of ambient temperature
- If not within 10% of ambient temperature
- Verify the Sunload Sensor parameter changes while covering the B10B Sun Load Temperature and Ambient Light and Security Indicator Sensor with a shop towel or other suitable item.
- If the Sunload Sensor parameter does not change
Refer to DTC B10FA or B1141 .
- Go to next step: If the Sunload parameter changes
- If the Sunload Sensor parameter does not change
- Verify the scan tool parameters listed below are within 10% of actual conditions.
- Passenger Compartment Humidity
- Passenger Compartment Humidity Sensor Temperature
- Windshield Temperature
- If not within 10% of actual conditions
Replace the B160 Inside Air Moisture and Windshield Temperature Sensor.
- Go to next step: If within 10% of actual conditions
- Install the appropriate Air Conditioning Recharge Service Center. Ignition ON.
- Verify the scan tool ECM Air Conditioning High Side Pressure Sensor parameter is within 10% of the high side pressure gauge reading on the Air Conditioning Service Center.
- If the reading is not within 10%
Refer to DTC P0532 or P0533 .
- Go to next step: If the reading is within 10%
- If the reading is not within 10%
- 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
- Verify the Q2 Air Conditioning Clutch is engaged.
- If the Q2 Air Conditioning Clutch is not engaged, refer to Air Conditioning Compressor Malfunction .
- If the Q2 Air Conditioning Clutch is engaged, refer to Air Conditioning (A/C) System Performance Test
- 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
- If the air is not warm
- A fault is not currently present and may be an intermittent condition.