Test H: Incorrect/Erratic Direction of Airflow From Outlets - EATC
PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLETS - EATCNormal Operation
Under normal operation, the automatic temperature control (ATC) solenoid and manifold receives a ground from the HVAC module - electronic automatic temperature control (EATC) through circuit RH226 (WH/VT). Depending on which solenoid is to be energized, the ATC solenoid and manifold receives voltage from the HVAC module - EATC through circuits:
- CH220 (GN/BN) for the air inlet door vacuum control motor.
- CH221 (GY/VT) for the defrost door vacuum control motor.
- CH222 (WH/VT) for the floor door vacuum control motor.
- CH223 (YE/BU) for the panel door vacuum control motor.
- CH224 (BU/OG) for the heater control valve.
Engine vacuum is supplied to the ATC solenoid and manifold. When one of the solenoids is energized, vacuum is applied to the control motor or valve and the desired door or valve is either opened or closed.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ATC solenoid and manifold
- HVAC module - EATC
- Heater control valve
- Vacuum control motor
- Stuck or bound linkage or door
- Leaking or plugged vacuum hose
H1-H3:
H4-H6:
H7-H9:
H9-H11:
H11-H14:
H14-H16:
H16-H17:
