Owners of 2013 Chevy Spark vehicles may comment on the A/C blowing warm air intermittently out of the ducts when driving at highway speeds and more noticeably on longer commutes with high humidity.
This condition may be caused by the evaporator freezing to the point that air flow may not be able to pass through the evaporator. If the vehicle was built after Nov. 21, 2012, verify the vehicle has the latest calibrations in the BCM for the HVAC system. If not, update the BCM software with the current calibration in TIS2Web. Refer to Body Control Module Programming and Setup in the service manual.
If the vehicle was built prior to Nov. 21, 2012, replace the temperature cam link and the evaporator air temperature (EAT) sensor as follows:
1. Replace the WHITE temperature cam link with a BLACK cam link. If the temperature cam link is black and the vehicle was built prior to Nov. 22, 2012, this procedure has already been performed.
2. Remove the EAT sensor by turning the top of the sensor left and pull out.
3. Disconnect the wiring connector from the sensor.
4. Install the new sensor with the arrow at the 9 o’clock position, then turn right to the 12 o’clock position.
5. Connect the wiring connector.
To determine if a new EAT sensor has already been installed, the new EAT sensor will be bent upwards and to the left of the base arrow. The new sensor is natural in color.