Chrysler 300M 2002 Service Manual page 1654

LH
EVAPORATOR TEMPERATURE SENSOR (Continued)
REMOVAL
(1) Open the hood and disconnect the negative bat-
tery cable remote terminal from the remote battery
post (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/
CABLES - REMOVAL).
(2) Remove the right under panel silencer.
(3) Disconnect the wiring connector for the evapo-
rator probe.
(4) At the center of the HVAC housing, locate the
evaporator probe access plate. Using a flat blade pry
tool, pull back on the locking tab. Twist the access
plate counter clockwise one-quarter turn, and push
the plate inside the HVAC housing (Fig. 13).
Fig. 13 EVAPORATOR PROBE NEEDLE
1 - EVAPORATOR PROBE
(5) Orient the plate in such a way that allows it to
be pulled through the mounting hole, and remove it.
(6) Pull the evaporator probe out of evaporator
core.
INSTALLATION
The new probe must not go into the same
hole (in the evaporator coil) that the old probe
was removed.
(1) The evaporator is manufactured with three
holes for probe insertion. Insert the probe in the
uppermost hole.
(2) Insert the access plate inside the HVAC hous-
ing and orientate it so that the locking tab is one-
quarter turn clockwise to where the tab snaps into
the HVAC case detent. Note that the plate will be
flush with the outside of the HVAC housing.
(3) Turn the plate one-quarter turn counter clock-
wise to seat the locking tab in the HVAC case detent.
(4) Connect the wiring harness connector for the
evaporator probe.
(5) Install the right under panel silencer.
(6) Connect the negative battery cable remote termi-
nal to the remote battery post(Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/CABLES - INSTALLATION).
IN-CAR TEMPERATURE
SENSOR
DESCRIPTION
The Automatic Temperature Control (ATC) in-car
temperature sensor returns electrical signals to the
Body Control Module (BCM). The in-car temperature
sensor is used on ATC equipped vehicles only. The in-
car temperature sensor is made up of two parts. One
part is the in-car sensor aspirator motor assembly,
and the second part is a temperature thermistor. The
in-car sensor aspirator motor assembly attaches to
the back of the ATC Control head (Fig. 14). This
assembly has a small fan and a motor which draws
air through the intake on the front of the ATC con-
trol. The in-car sensor thermistor is located inside of
the ATC Control Head. The in-car sensor aspirator
motor is part of the ATC Control and not a separate
serviceable part. The ATC Control must be replaced
if there is a fault relating to the motor. The in-car
temperature sensor thermistor is part of the ATC
Control and not a separate serviceable part. One
must replace the ATC Control if the ATC self-diag-
nostics indicates a fault code. (Refer to 24 - HEAT-
ING & AIR CONDITIONING - DIAGNOSIS AND
TESTING - SELF DIAGNOSTICS)
Fig. 14 ATC IN-CAR TEMPERATURE SENSOR
1 - ATC IN-CAR TEMPERATURE SENSOR
OPERATION
Air drawn from the passenger compartment by the
in-car sensor aspirator motor assembly, and flows
over the thermistor. The in-car sensor thermistor
changes resistance with air temperature. The BCM
measures this resistance and calculates the tempera-
ture of the air drawn into the ATC Control. The ATC
system then makes adjustments to maintain the opti-
mum passenger compartment comfort. Refer to the
ATC In-Car Sensor Aspirator Motor Operation table
for when the ATC Sensor is operating.
CONTROLS 24 - 17