Volt

HVAC System Malfunction

Check the following mechanical fault sources:

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Note: Check for bulletins before proceeding.

1. Vehicle in Service Mode, place the blower motor switch in each speed position. Verify that the blower motor operates properly in each position.

⇒	If the blower motor does not operate properly in all speeds, refer to DTC B0193 .

2. Using the scan tool observe the mode, temperature, air inlet and recirculation door positions. Verify the actual and commanded door positions are within 4 counts of each other.

⇒	If not within the specified range, refer to Circuit/System Testing DTC B0223, B0233, B023A, or B0408 .

3. Engine ON, A/C ON, place the temperature control in the coldest position. Verify that cool air flows from the ducts in the vehicle.

⇒	If the air is not cool, refer to Air Conditioning (A/C) System Performance Test .

4. Turn the A/C OFF and place the temperature control in the warmest position.

⇒	If the air is insufficiently heated refer to Heating Performance Diagnostic .

5. Engine OFF, Vehicle in Service Mode, cover the sunload sensor assembly with a workshop towel or other suitable item. Verify the scan tool Sunload Sensor parameter changes.

⇒	If it does not change, refer to Circuit/System Testing DTC B0183 .

6. Measure actual inside air temperature using a thermometer. Compare this value to the scan tool Inside Passenger Compartment Air Temp. Sensor parameter. The measured temperature should be within 5 degrees of parameter.

⇒	If not within the specified range, refer to Circuit/System Testing DTC B0163 .

7. Vehicle in Service Mode, observe the scan tool A/C Evaporator Temperature Sensor parameter. The reading should be between -39°F and 185°F and change with evaporator air temperature changes.

⇒	If not within the specified range, refer to Circuit/System Testing DTC B0173, B0178, or B3933 or DTC P0536-P0538 or P153B .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.