Chrysler 300M 2002 Service Manual page 1737

GENERAL INFORMATION
The ATS is a variable resistor that operates on a
5-volt reference signal circuit hardwired from the
BCM. The resistance in the ATS changes as the
outside temperature rises or falls. The BCM senses
the change in reference voltage through the ATS
resistor. Based on the resistance of the ATS, the
BCM is programmed to correspond to a specific
temperature. The BCM stores and filters the ambi-
ent temperature data and transmits this data to the
CMTC/EVIC via the PCI Bus. The ATS cannot be
adjusted or repaired and, if faulty or damaged, it
must be replaced.
AMBIENT TEMPERATURE SENSOR FAULT
CODES
The outside temperature function is supported by
the ambient temperature sensor (ATS), a signal and
ground circuit hardwired to the PCM, and the
CMTC/EVIC display.
If the CMTC/EVIC display indicates 54°C (130°F)
or the ATS sense circuit is shorted to ground, the
temp display will be 54°C (130°F) to indicate a
SHORT circuit condition.
If the CMTC/EVIC display indicates -40°C
(-40°F) or the ATS sense circuit is open, the temp
display will be -40°C (-40°F) to indicate an OPEN
circuit condition.
If there is an OPEN or SHORT circuit condition,
it must be repaired before the CMTC/EVIC VFD
can be tested.
The ATS is supported by the PCM. Ambient
Temperature Sensor DTCs will be recorded in the
PCM. The ATS can be diagnosed using the following
Sensor Test. Test the ATS circuits using the diag-
nostics in the Body Diagnostic Procedures Manual.
If the CMTC/EVIC passes the self test, and the ATS,
the circuits, and PCI bus communications are con-
firmed to be OK, but the CMTC/EVIC temperature
display is inoperative or incorrect, replace the PCM.
AMBIENT TEMPERATURE SENSOR TEST
1. Turn the ignition OFF.
2. Disconnect the ATS harness connector.
3. Measure the resistance of the ATS using the
following min/max values:
• 0° C (32° F) Sensor Resistance = 29.33 - 35.99
Kilohms
• 10° C (50° F) Sensor Resistance = 17.99 - 21.81
Kilohms
• 20° C (68° F) Sensor Resistance = 11.37 - 13.61
Kilohms
• 25° C (77° F) Sensor Resistance = 9.12 - 10.86
Kilohms
•
30° C (86° F) Sensor Resistance = 7.37 - 8.75
Kilohms
• 40° C (104° F) Sensor Resistance = 4.90 - 5.75
Kilohms
The sensor resistance should read between these
min/max values. If the resistance values are not
OK, replace the Sensor.
3.11.6 HOMELINK UNIVERSAL
TRANSMITTER
If equipped, the HomeLink Universal Transmit-
ter is integrated into the overhead console. For
added security it will operate home security sys-
tems that use coded signals known generically as
Rolling Codes. The overhead console display pro-
vides visual feedback to the driver, indicating which
HomeLink transmitter channel button is being
pressed. The HomeLink can learn and store up to
three separate transmitter radio frequency codes to
operate garage door openers, security gates, and
security lighting. The HomeLink
marked with one, two, or three dots. For complete
information, refer to Universal Transmitter in the
Service Manual or the Owner's Manual.
3.12 TIRE PRESSURE MONITORING
SYSTEM (TPM)
If equipped with the Tire Pressure Monitoring
System (TPM), each of the vehicles five wheels will
have a valve stem with an integral pressure sensor
and radio transmitter. Radio signals from the tire
pressure sensor/transmitters are received and in-
terpreted by the Electronic Vehicle Information
Center (EVIC).
A sensor/transmitter in a mounted wheel will
broadcast its detected pressure once per minute
when the vehicle speed is greater than 40 km/h (25
mph). The spare tire sensor will broadcast once
every hour. Each sensor's broadcast is uniquely
coded so that the EVIC can determine location. The
individual tire pressures can be displayed graphi-
cally on the EVIC.
3.12.1 TRAINING THE EVIC
The EVIC can be trained to recognize the source
locations of pressure sensor/transmitter signals.
Use the following training procedure:
1. Locate RETRAIN TIRE SENSORS
EVIC menu.
2. Press STEP button to select YES and MENU
button to confirm.
When this mode is enabled by selecting YES , the
EVIC will initiate the training procedure.
3. The EVIC display will prompt the user to:
TRAIN LEFT FRONT TIRE . At this point the
user must set the left front tire sensor to learn
14
buttons are
on the