2014 Jeep Wrangler JK Factory Service Manual 24 - Heating and Air Conditioning

SENSOR, Sun

DESCRIPTION



NOTE:

Typical sun sensor assembly shown.


The Automatic Temperature Control (ATC) heating-A/C system uses a sun sensor (1) to measure sun light intensity. The sun sensor incorporates three sun load sensors (2) within a molded plastic case which is mounted to the instrument panel and a clear lens (3) that protrudes through the defroster grille. The wire harness receptacle (4) connects the sun sensor to the vehicle electrical system.

OPERATION

The ATC heating-A/C system uses two sun sensors to balance the system in response to side-to-side variations in sun light intensity. Passengers in sun and shadow require different functional settings because they experience very different temperatures. The sun sensor assembly provides data to the A/C heater control to help determine proper mode and blend-air door positions and blower motor speeds. The sun sensors are not thermistor type sensors, but rather photo diodes. For this reason the sun sensors responds to sun light intensity rather than temperature. The sun sensor assembly is also used to sense day and night conditions for automatic headlight control, when equipped.

The sun sensor is diagnosed using a scan tool (Refer to 28 - DTC-Based Diagnostics/HVAC - Diagnosis and Testing) .

The sun sensor assembly cannot be adjusted or repaired and must be replaced if inoperative or damaged.

DIAGNOSIS AND TESTING - SUN SENSOR

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. 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 possible serious or fatal injury.

The sun sensor is located so that the sun rays will hit the sensors in the same way that it will hit the driver and the passenger. If the vehicle exhibits a lack of passenger comfort in sunny weather such as in the early afternoon, inspect the area around the sun sensor on top of the dash panel. It is important that the area of the sun sensor be unobstructed from plain view. Check for the following:

The A/C-heater control continually monitors the sun sensor circuits and will store Diagnostic Trouble Codes (DTCs) for any problem it detects. The sun sensor can be tested in the vehicle with a scan tool (Refer to 28 - DTC-Based Diagnostics/HVAC - Diagnosis and Testing) .

REMOVAL

Special Tools: Click to display a list of tools used in this procedure

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. 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 possible serious or fatal injury.


  1. Disconnect and isolate the negative battery cable.

    2.  
  2. Using Trim Stick C-4755 or equivalent, remove the sun sensor (1) from the defroster grille (2).

    3.  
  3. Disconnect the wire harness connector (2) from the sun sensor (1) and remove the sensor.

    4.  

INSTALLATION

  1. Position the sun sensor (1) to the top of the instrument panel and connect the wire harness connector (2) to the sensor.

    2.  
  2. Align the tab on the sun sensor (1) with the slot in the opening in the defroster grille (2) and install the sensor onto the grille. Make sure that the sensor is fully engaged to the defroster grille.

    3.  
  3. Reconnect the negative battery cable.

    4.