Fault Code 1, 2 & 4

Fig. 12 ATC wiring harness and lead connectors:

1. Remove blend-air door actuator, then with wore connector still connected, retest system. If code is not displayed, check for blend-air door binding and correct as necessary. If code(s) still appear, proceed to step 2.
2. Disconnect wire connector from blend-air door actuator and computer control, then remove computer control.
3. Using a suitable ohmmeter, check for continuity between pins of terminals shown, as follows:
a. Pin 1 of 1 to pin 6 of 8.
b. Pin 2 of 1 to pin 11 of 8.
c. Pin 3 of 1 to pin 5 of 8.
d. Pin 4 of 1 to pin 8 of 7.
If circuits are complete, replace blend-air door actuator, then retest system. If failure code is still present, replace computer control. If any circuits show no continuity, proceed to step 4.
4. Using a suitable ohmmeter, check for continuity between pins of terminals shown, as follows:
a. Pin 1 of 1 to pin 3 of 2.
b. Pin 2 of 1 to pin 4 of 2.
c. Pin 3 of 1 to pin 5 of 2.
d. Pin 4 of 1 to pin 1 of 2.
If any circuits are open, repair harness lead between connectors 2 and 1. If circuits are complete, proceed to step 5.
5. Using a suitable ohmmeter, check for continuity between pins of terminals shown, as follows:
a. Pin 3 of 3 to pin 6 of 8.
b. Pin 4 of 3 to pin 11 of 8.
c. Pin 5 of 3 to pin 5 of 8.
d. Pin 1 of 3 to pin 8 of 7.
If any circuits are open, repair main wire harness. If all circuits are complete, reconnect all electrical connectors, then retest system. If failure code is still present, replace blend-air door actuator, then retest system. If failure code is still present, replace blend-air door actuator, then retest system. If failure code is still present, replace computer control.