Test H: Incorrect/Erratic Direction Of Airflow From Outlets
PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLETSNormal Operation
Under normal operation, to rotate the mode door actuator clockwise, the electronic manual temperature control (EMTC) module or HVAC module - dual automatic temperature control (DATC) supplies voltage to the FLOOR/DEFROST/PANEL mode door actuator motor through the circuit CH228 (YE/GY), and supplies ground through circuit CH229 (WH/BU). To rotate the mode door actuator counterclockwise, the HVAC module - EMTC or HVAC module - DATC reverses the voltage and ground circuits.
The mode door actuator feedback resistor is supplied a ground from the HVAC module - EMTC or HVAC module - DATC through circuit RH111 (GY/BU) and a 5-volt reference voltage on circuit LH111 (BN/WH). The HVAC module - EMTC or HVAC module - DATC reads the voltage on the mode door actuator feedback circuit VH436 (YE/VT) to determine the mode door actuator position by the position of the actuator feedback resistor wiper arm.
- DTC B1003 Mode Door Short/Failure - The module senses no change in actuator feedback voltage when the actuator motor has been energized.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Mode door actuator
- HVAC module - DATC
- HVAC module - EMTC
- Stuck or bound linkage or door
H1-H2:
H2-H3:
H4-H5:
H6-H8:
H8-H10:
H10-H12:
H12-H13:
H14-H15:
H16-H18:
