Test D

PINPOINT TEST D: DTC B1263 MODE DOOR FAILURE / INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET(S)

Test D1-D3:

Test D4-D5:

Test D6-D8:

Test D8-D10:

Test D10-D12:

Test D12-D13:

Test D13-D14:

Test D14-D15:

Test D15-D16:

Test D17-D18:

Normal Operation
Under normal operation, to rotate the mode door actuator clockwise, the EMTC module or EATC module supplies voltage to the Floor/Defrost/Panel mode door actuator motors through the circuit 1989 (OG/LB), and supplies ground through circuit 1988 (BN/OG). To rotate the mode door actuator counterclockwise, the EMTC module or EATC module reverses the voltage and ground circuits.

The mode door actuator feedback resistor is supplied a ground from the EMTC module or EATC module through circuit 1978 (BN/LG) and a 5-volt reference voltage on circuit 1977 (YE/BK). The EMTC module or EATC module reads the voltage on the mode door actuator feedback circuit 1982 (LB/BK) to determine the mode 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 1988 (BN/OG), 1989 (OG/LB), 1982 (LB/BK), 1978 (BN/LG), 1977 (YE/BK) and 1982 (LB/BK).
- Floor/defrost/panel mode door actuator motor.
- EATC module.
- EMTC module.
- Stuck or bound linkage or door.