Test T: The Auxiliary Temperature Control Is Inoperative/Does Not Operate Correctly Using the Front/Rear Auxiliary Climate Cont

PINPOINT TEST T: THE AUXILIARY TEMPERATURE CONTROL IS INOPERATIVE/DOES NOT OPERATE CORRECTLY USING THE FRONT/REAR AUXILIARY CLIMATE CONTROLS

T1:

T1-T2:

T3-T4:

T4-T5:

T5-T7:

T7-T8:

T8-T10:

T10-T12:

T12-T14:

T14 Continued:

T15-T17:

T17-T18:

Normal Operation
Under normal operation, to rotate the temperature door actuator clockwise, the electronic manual temperature control (EMTC) or electronic automatic temperature control (EATC) module supplies voltage to the auxiliary temperature door actuator through the circuit CH233 (VT/BN), and supplies ground through circuit CH234 (YE/GN). To rotate the auxiliary temperature door actuator counterclockwise, the EMTC or EATC module reverses the voltage and ground circuits.

The auxiliary temperature door actuator feedback resistor is supplied a ground from the EMTC or EATC module through circuit RH111 (GY/BU) and a 5-volt reference voltage on circuit LH111 (BN/WH). The EMTC or EATC module reads the voltage on the auxiliary temperature door actuator feedback circuit VH439 (GY/VT) to determine the auxiliary temperature door actuator position by the position of the actuator feedback resistor wiper arm.

The auxiliary temperature control is supplied a 5-volt reference through circuit LH111 (BN/WH) and ground through circuit RH111 (GY/BU). When the temperature control is adjusted, the EMTC or EATC receives the signal through circuit VHA15 (YE/GY).

Possible Causes
- An open, short to voltage, ground or together in circuits CH233 (VT/BN), CH234 (YE/GN), RH111 (GY/BU), LH111 (BN/WH) and VH439 (GY/VT)
- A short to ground in circuits CH233 (VT/BN), CH234 (YE/GN), LH111 (BN/WH) and VH439 (GY/VT)
- A short to voltage in circuits CH233 (VT/BN), CH234 (YE/GN), RH111 (GY/BU) and VH439 (GY/VT)
- A short together in circuits CH233 (VT/BN), CH234 (YE/GN), RH111 (GY/BU), LH111 (BN/WH) and VH439 (GY/VT)
- Auxiliary temperature door actuator
- EATC module
- Stuck or bound linkage or door