2012 Jeep Wrangler JK Factory Service Manual 24 - Heating and Air Conditioning

ACTUATOR, Blend Door

DESCRIPTION

DESCRIPTION

The blend 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 blend-air door. The blend door actuator is located on the left side of the HVAC air distribution housing.

The blend door actuator is contained within a black molded plastic housing with an integral wire connector receptacle (2). An output shaft (3) with splines connect it to the blend door linkage and integral mounting tabs (4) allow the actuator to be secured to the HVAC housing. The blend door actuator does not require mechanical indexing to the blend-air door, 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 (Refer to 28 - DTC-Based Diagnostics/HVAC - Standard Procedure) .

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

OPERATION

OPERATION

The blend 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 blend door actuator can move the blend-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 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. Once the A/C-heater control makes the voltage to both connections high or both connections low, the blend-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 blend door actuator and the blend-air door. The A/C-heater control learns the blend-air door 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 (Refer to 28 - DTC-Based Diagnostics/HVAC - Diagnosis and Testing) .

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

REMOVAL

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.




NOTE:

LHD model shown. RHD model similar.

  1. Disconnect and isolate the negative battery cable.

    2.  
  2. On RHD models, remove the two push-pins and silencer panel from the passenger side of the instrument panel.

    3.  
  3. On RHD models, remove the glove box bin (Refer to 23 - Body/Instrument Panel/GLOVE BOX, Instrument Panel - Removal) .

    4.  
  4. Disconnect the wire harness connector (1) from the blend door actuator (2) located on the left side of the HVAC air distribution housing (3).

    5.  
  5. Remove the two screws (4) that secure the blend door actuator to the air distribution housing and remove the actuator.

    6.  

INSTALLATION

INSTALLATION

NOTE:

LHD model shown. RHD model similar.

  1. Position the blend door actuator (2) onto the left side of the HVAC air distribution housing (3). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those in the blend air door linkage.

    2.  
  2. Install the two screws (4) that secure the blend door actuator to the air distribution housing. Tighten the screws to 2 N·m (17 in. lbs.).

    3.  
  3. Connect the wire harness connector (1) to the blend door actuator.

    4.  
  4. On RHD models, install the glove box bin (Refer to 23 - Body/Instrument Panel/GLOVE BOX, Instrument Panel - Installation) .

    5.  
  5. On RHD models, install the silencer panel and two push-pins.

    6.  
  6. Reconnect the negative battery cable.

    7.  
  7. Initiate the Actuator Calibration function using a scan tool (Refer to 28 - DTC-Based Diagnostics/HVAC - Standard Procedure) .

    8.