Dodge Nitro. Manual — part 743

Fig. 50: Evaporator Temperature Sensor, A/C Evaporator, HVAC Housing & Connector Receptacle
Courtesy of CHRYSLER LLC

The evaporator temperature sensor (1) measures the temperature of the conditioned air downstream of the A/C
evaporator (2). The evaporator temperature sensor is an electrical thermistor within a molded plastic case that is
inserted into rear the HVAC housing (3) near the coldest point of the A/C evaporator. Two terminals within the
connector receptacle (4) connect the sensor to the vehicle electrical system through a wire lead and connector of
the instrument panel wire harness.

The external location of the evaporator temperature sensor allows the sensor to be removed or installed without
disturbing the refrigerant in the A/C system.

OPERATION

NOTE:

Typical evaporator temperature sensor shown.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

SENSOR-EVAPORATOR TEMPERATURE

The evaporator temperature sensor monitors the temperature of the conditioned air downstream of the A/C
evaporator and supplies an input signal to the A/C-heater control. The A/C-heater control uses the evaporator
temperature sensor input signal to optimize A/C system performance and to protect the A/C system from
evaporator freezing. The evaporator temperature sensor will change its internal resistance in response to the
temperatures it monitors and is connected to the A/C-heater control through sensor ground circuit and a 5-volt
reference signal circuit. As the temperature of the A/C evaporator decreases, the internal resistance of the
evaporator temperature sensor decreases.

The A/C-heater control uses the monitored voltage reading as an indication of evaporator temperature. The
A/C-heater control is programmed to respond to this input by requesting the powertrain control module (PCM)
or the engine control module (ECM) (depending on engine application) to cycle the A/C compressor clutch as
necessary to optimize A/C system performance and to protect the A/C system from evaporator freezing.

The evaporator temperature sensor is diagnosed using a scan tool. See HEATING & AIR CONDITIONING -
ELECTRICAL DIAGNOSTICS for more information.

The evaporator temperature sensor cannot be adjusted or repaired and must be replaced if found inoperative or
damaged.

REMOVAL

SENSOR-EVAPORATOR TEMPERATURE

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:

Illustration shown with instrument panel removed for clarity.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 51: Removing/Installing Evaporator Temperature Sensor From Front Of HVAC Housing
Courtesy of CHRYSLER LLC

1. Disconnect and isolate the negative battery cable.

2. Partially remove the instrument panel to gain access to the evaporator temperature sensor (1) located in

the rear of the HVAC housing (2), near the bottom of the instrument panel on the passenger side. Refer to
REMOVAL .

3. Disconnect the instrument panel wire harness connector from the evaporator temperature sensor and

remove the sensor from the HVAC housing.

INSTALLATION

SENSOR-EVAPORATOR TEMPERATURE

NOTE:

LHD model shown. RHD model similar.

NOTE:

Illustration shown with instrument panel removed for clarity.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 52: Removing/Installing Evaporator Temperature Sensor From Front Of HVAC Housing
Courtesy of CHRYSLER LLC

1. Install the evaporator temperature sensor (1) into rear of the HVAC housing (2) and connect the

instrument panel wire harness connector.

2. Install the instrument panel. Refer to INSTALLATION .

3. Reconnect the negative battery cable.

SENSOR-INFRARED

DESCRIPTION

SENSOR-INFRARED

Fig. 53: Infrared Temperature Sensor, Integral Wire Connector Receptacle, Alignment Tabs & Clear
Lens
Courtesy of CHRYSLER LLC

The infrared temperature sensor (1) consists of an infrared transducer concealed behind a clear lens (4) located
in a molded plastic housing with an integral wire connector receptacle (2) and mounting and alignment tabs (3
and 5).

The infrared sensor is used only on models equipped with the automatic temperature control (ATC) heating-
A/C system.

OPERATION

SENSOR-INFRARED

The infrared sensor detects thermal radiation emitted by the driver and front seat occupants and surroundings

NOTE:

LHD model shown. RHD model similar.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro