Ambient Temperature Sensor Description; Operation; Diagnosis And Testing - Ambient Temperature Sensor; Removal - Chrysler Concorde 2004 Service Manual

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UNIVERSAL TRANSMITTER (Continued)
(4) When the red light on the universal transmit-
ter begins to flash rapidly (this may take as long as
60 seconds), release both buttons. Your universal
transmitter is now "trained". To train the other but-
tons, repeat Step 3 and Step 4. Be sure to keep your
hand-held transmitter in case you need to retrain the
universal transmitter.
AMBIENT TEMPERATURE
SENSOR
DESCRIPTION
Fig. 10 Ambient Temperature Sensor
Ambient air temperature is monitored by the Elec-
tronic Vehicle Information Center (EVIC) through
ambient temperature messages received from the
Powertrain Control Module (PCM) over the Program-
mable Communications Interface (PCI) data bus net-
work. The PCM receives a hard wired input from the
ambient temperature sensor (Fig. 10). The ambient
temperature sensor is a variable resistor mounted to
a bracket that is secured with a screw to the right
side of the headlamp mounting module grille open-
ing, behind the radiator grille and in front of the
engine compartment.
Refer to Powertrain Control Module in Elec-
tronic Control Modules for more information. For
complete circuit diagrams, refer to the appropriate
wiring information. The ambient temperature sensor
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.

OPERATION

The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the Powertrain Control Module (PCM).
The resistance in the sensor changes as temperature
changes, changing the temperature sensor signal cir-
cuit voltage to the PCM. Based upon the resistance
in the sensor, the PCM senses a specific voltage on
the temperature sensor signal circuit, which it is pro-
grammed to correspond to a specific temperature.
MESSAGE SYSTEMS 8M - 15
The PCM then sends the proper ambient tempera-
ture messages to the EVIC over the PCI data bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Powertrain Control Module (PCM), the Programma-
ble Communications Interface (PCI) data bus, and a
portion of the Electronic Vehicle Information Center
(EVIC) module. If any portion of the ambient temper-
ature sensor circuit fails, the PCM will self-diagnose
the circuit.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At room temperature (approx. 68°F),
the sensor resistance should be between 9-11 Kilo-
hms (9000-11000 ohms). The sensor resistance should
read between these two values. If OK, the sensor is
OK at this time. If not OK, replace the faulty ambi-
ent temperature sensor.

REMOVAL

(1) Open hood, disconnect and isolate the negative
battery cable remote terminal from the remote bat-
tery post (Fig. 11).
Fig. 11 Negative Battery Cable Remote Terminal
1 - RIGHT STRUT TOWER
2 - AIR CLEANER INLET TUBE
3 - REMOTE TERMINAL
(2) Raise and support the vehicle on safety stands.
(3) From behind front bumper fascia, remove the
screw attaching the ambient temperature sensor to
radiator closure panel.