Fault Code 12 and/or 13

1. Disconnect electrical connector from blend-air door actuator.
2. Remove ATC control, then disconnect electrical connector and check for continuity between the following pins:
a. ATC control pin 12 and blend-air door actuator pin 2.
b. ATC control pin 17 and blend-air door actuator pin 3.
c. ATC control pin 18 and blend-air door actuator pin 1.
3. If continuity does not exist, repair affected circuit and recheck system. If all circuits are satisfactory, replace blend-air door actuator and recheck system. If failure is still present, replace ATC control and recheck system.