Fault Code 1, 2 or 3

If failure code 12 or 13 is present with any of these codes, repair code 12 or 13 first, then retest. If failure code 3 is displayed, begin diagnosis with step 2.

1. Remove blend-air door actuator and recheck system operation with electrical connector connected. If code(s) are no longer displayed, check for blend-air door in A/C housing binding and correct as necessary. If code(s) still appear, proceed to step 2.

2. Disconnect electrical connectors and using a suitable ohmmeter, check for continuity between pins of terminals shown as follows:
a. Pin 3 of blend-air door actuator to pin 17 of ATC control.
b. Pin 1 of blend-air door actuator to pin 18 of ATC control.
c. Pin 4 of blend-air door actuator to pin 8 of ATC control.
d. Pin 5 of blend-air door actuator to pin 7 of ATC control.
e. Pin 2 of blend-air door actuator to pin 12 of ATC control.
Repair any open circuits, then retest system. If all circuits are satisfactory, reconnect electrical connectors, then proceed to step 3 with failure code 1, step 4 with failure code 2 or step 5 with failure code 3.

3. Set ATC control to 65, then after a minimum of 30 seconds, connect voltmeter positive lead to ATC control connector pin 8 and negative lead to pin 7. Raise temperature setting to 85 and note voltage. If voltage increases to more than 4 volts and stops and a fail code 1 is issued, replace ATC control. If voltage does not increase as described, proceed to step 5.
4. Set ATC control to 85, then after a minimum of 30 seconds, connect voltmeter positive lead to ATC control connector pin 8 and negative lead to pin 7. Lower temperature setting to 65 and note voltage. If voltage slowly decreases to less than 1 volt and a fail code 2 is issued, replace ATC control. If voltage does not decrease, proceed to step 5.
5. Replace blend-air door actuator and retest. If failure code(s) still exist, replace ATC control.