DESCRIPTION

Fig. 12: Blend Door Actuators

The mode door actuator (1) for the heating-A/C system is a reversible, 12-volt Direct Current (DC) servo motor, which is mechanically connected to the mode-air doors. The mode door actuator is located on the right side of the HVAC air distribution housing.

The mode door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2). An output shaft with splines (3) connect it to mode door linkage and integral mounting tabs (4) allow the actuator to be secured to the air distribution housing. The mode door actuator does not require mechanical indexing to the mode-air doors, as it is electronically calibrated by the A/C-heater control.

The A/C-heater control must be recalibrated each time an actuator motor is replaced.

The mode door actuator is interchangeable with the actuators for the recirculation and blend-air doors.

OPERATION

The mode door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the instrument panel wire harness. The mode door actuator can move the mode-air door in two directions. When the A/C-heater control pulls the voltage on one side of the motor connection high and the other connection low, the mode-air door will move in one direction. When the A/Cheater control reverses the polarity of the voltage to the motor, the mode-air door moves in the opposite direction. Once the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air door stops and will not move.

The A/C-heater control uses a pulse-count positioning system to monitor the operation and relative position of the mode door actuator and the mode-air door. The A/C-heater control learns the mode-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the mode door actuator circuits.

The mode door actuator cannot be adjusted or repaired and it must be replaced if inoperative or damaged.

REMOVAL

WARNING: Disable the airbag system before attempting any steering wheel, steering column or instrument panel component diagnosis or service. Disconnect and isolate the negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to follow these instructions may result in accidental airbag deployment and possible serious or fatal injury.

Fig. 13: Mode Door Actuator Removal/Installation

NOTE: LHD model shown. RHD model similar.

1. Disconnect and isolate the negative battery cable.

2. Remove the glove box bin.

3. Remove the screws (1) that secure the mode door actuator (4) to the bracket (5) located on the right side of the HVAC air distribution housing (2).

4. Disconnect the wire harness connector (3) from the mode door actuator and remove the actuator.

INSTALLATION

Fig. 14: Mode Door Actuator Removal/Installation

1. Position the mode door actuator (4) onto the bracket (5) located on the right side of the HVAC air distribution housing (2). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those in the mode air door linkage.

2. Install the screws (1) that secure the mode door actuator to the air distribution housing. Tighten the screws to 2 N.m (17 in. lbs.).

3. Connect the wire harness connector (3) to the mode door actuator.

4. Install the glove box bin.

5. Reconnect the negative battery cable.

6. Initiate the Actuator Calibration function using a scan tool.