Test R: The Auxiliary Temperature Control Only Is Inoperative/Does Not Operate Correctly

PINPOINT TEST R: THE AUXILIARY TEMPERATURE CONTROL ONLY IS INOPERATIVE/DOES NOT OPERATE CORRECTLY

R1-R2:

R3-R4:

R5-R7:

R7-R9:

R9-R11:

R11-R12:

R12-R13:

R14-R15:

R15-R17:

R17 Continued:

Normal Operation
Under normal operation, to rotate the mode door actuator clockwise, the EATC module supplies voltage to the auxiliary temperature door actuator through the circuit 1376 (BK/LB), and supplies ground through circuit 1375 (PK/YE). To rotate the auxiliary temperature door actuator counterclockwise, the EATC module reverses the voltage and ground circuits.

The auxiliary temperature door actuator feedback resistor is supplied a ground from the EATC module through circuit 1377 (TN/LG) and a 5-volt reference voltage on circuit 1381 (WH/LB). The EATC module reads the voltage on the auxiliary temperature door actuator feedback circuit 1378 (GY/WH) to determine the auxiliary temperature door actuator position by the position of the actuator feedback resistor wiper arm.

Possible Causes
- An open, short to voltage, ground or together in circuits 1376 (BK/LB), 1375 (PK/YE), 1377 (TN/LG), 1381 (WH/LB) and 1378 (GY/WH)
- Auxiliary temperature door actuator
- EATC module
- Stuck or bound linkage or door