ACTUATOR-BLEND DOOR
DESCRIPTION
The blend door actuators (1) are reversible, 12 volt direct current (DC), servo motors. Models equipped with the MTC single zone heating-A/C system have a single blend-air door, which is controlled by a single blend door actuator. Models with the ATC dual zone heating-A/C system have two blend-air doors, which are controlled by two blend door actuators.
The blend door actuator for the single zone heating-A/C system is located on the driver side end of the HVAC air distribution housing, close to the dash panel.
For the dual zone heating-A/C system, the same blend door actuator used for the single zone system becomes the driver side blend door actuator, which is mechanically connected to only the driver side blend-air door. A second separate blend door actuator is also located on the passenger side of the HVAC air distribution housing which is mechanically connected to only the passenger side blend-air door.
The blend door actuators are interchangeable with each other, as well as with the actuators for the mode-air door and the recirculation-air door. Each actuator is contained within an identical black molded plastic housing with an integral wire connector receptacle (2). Each actuator also has an identical output shaft with splines (3) that connects it to its respective door linkage and three integral mounting tabs (4) that allow the actuator to be secured to the HVAC housing. The blend door actuators do not require mechanical indexing to the blend-air doors, as they are electronically calibrated by the A/C-heater control.
OPERATION
The blend door actuators are connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the HVAC wire harness. The blend door actuator(s) can move the blend-air door(s) 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 blend-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the blend-air door moves in the opposite direction.
When the A/C-heater control makes the voltage to both connections high or both connections low, the blend-air door(s) 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 blend door actuators and the blend-air doors. The A/C-heater control learns the blend-air doors stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the blend door actuator circuits.
The blend door actuator(s) cannot be adjusted or repaired and must be replaced if found inoperative or damaged (refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING - HEATING AND A/C SYSTEMS and to 24 - HVAC Electrical Diagnostics for more information).
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 take the proper precautions could result in accidental airbag deployment and possible personal injury or death.
NOTE: The single zone heater-A/C system is equipped with a single blend door actuator. The dual zone system has two blend door actuators, one for the driver side blend-air door and one for the passenger side blend-air door.
SINGLE ZONE/DUAL ZONE LH SIDE
1. Disconnect and isolate the negative battery cable.
2. On LHD models, remove the instrument panel silencer from the driver side of the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL SILENCER - REMOVAL).
3. On RHD models, remove the glove box from the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/GLOVE BOX - REMOVAL).
4. Remove the three screws (1) that secure the blend door actuator (2) to the left side of the HVAC air distribution housing (3).
5. Remove the blend door actuator from the air distribution housing and disconnect the HVAC wire harness connector (4) from the actuator.
6. Remove the blend door actuator from the vehicle.
DUAL ZONE RH SIDE
NOTE: LHD model shown. RHD model similar.
1. Disconnect and isolate the negative battery cable.
2. On LHD models, remove the glove box from the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/GLOVE BOX - REMOVAL).
3. On RHD models, remove the instrument panel silencer from the driver side of the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL SILENCER - REMOVAL).
4. Remove the three screws (1) that secure the blend door actuator (2) to the right side of the HVAC air distribution housing (3).
5. Remove the blend door actuator from the air distribution housing and disconnect the HVAC wire harness connector (4) from the actuator.
6. Remove the blend door actuator from the vehicle.
INSTALLATION
NOTE: The single zone heater-A/C system is equipped with a single blend door actuator. The dual zone system has two blend door actuators, one for the driver side blend-air door and one for the passenger side blend-air door.
SINGLE ZONE/DUAL ZONE LH SIDE
1. Position the blend door actuator (1) into the vehicle.
2. Install the blend door actuator onto the left side of the HVAC air distribution housing (2). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft (3) with those on the blend door cam (4).
3. Install the screws (1) that secure the blend door actuator (2) to the left side of the air distribution housing (3). Tighten the screws to 2 N·m (17 in. lbs.).
4. Connect the HVAC wire harness connector (4) to the blend door actuator.
5. On LHD models, install the instrument panel silencer onto the driver side of the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL SILENCER - INSTALLATION).
6. On RHD models, install the glove box into the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/GLOVE BOX - INSTALLATION).
7. Reconnect the negative battery cable.
DUAL ZONE RH SIDE
NOTE: LHD model shown in illustrations. RHD model similar.
1. Position the blend door actuator (1) into the vehicle.
2. Install the blend door actuator onto 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 (3) with those on the blend door cam (4).
3. Install the screws (1) that secure the blend door actuator (2) to the right side of the air distribution housing (3). Tighten the screws to 2 N·m (17 in. lbs.).
4. Connect the HVAC wire harness connector (4) to the blend door actuator.
5. On LHD models, install the glove box into the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/GLOVE BOX - INSTALLATION).
6. On RHD models, install the instrument panel silencer onto the driver side of the instrument panel (refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL SILENCER - INSTALLATION).
7. Reconnect the negative battery cable.