temperature. The FCM 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.
3.15.7
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 FCM, and the
CMTC/EVIC display.
If 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 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 FCM. Ambient
Temperature Sensor DTCs will be recorded in the
FCM. 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
confirmed to be OK, but the CMTC/EVIC tempera-
ture display is inoperative or incorrect, replace the
FCM.
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.
3.15.8
HOMELINK
T UNIVERSAL
TRANSMITTER
If equipped, the HomeLink
t 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
t transmitter channel button is being
pressed. The HomeLink
t can learn and store up to
three separate transmitter radio frequency codes to
operate garage door openers, security gates, and
security lighting. The HomeLink
t buttons are
marked with one, two, or three dots. For complete
information, refer to Universal Transmitter in the
Service Manual or the Owner’s Manual.
3.15.9
TIRE PRESSURE MONITORING
SYSTEM (TPMS)
If equipped with the Tire Pressure Monitoring
System (TPMS), each of the vehicles four wheels
will have a valve stem with a pressure sensor and
radio transmitter built in. Signals from the tire
pressure Sensor/Transmitter are received and in-
terpreted by the Sentry Key Remote Entry Module
(SKREEM). Using the DRBIII
t, go to ANTI-THEFT
for the SKREEM data.
A Sensor/Transmitter in a mounted wheel will
broadcast an RF frequency indicating its pressure
once per minute when the vehicle is in drive mode.
To activate the Sensor/Transmitter operation, the
required SKREEM speed is 13 mph (20 km/h). Each
Sensor/Transmitters broadcast is uniquely coded so
that the SKREEM can monitor the states of each
Sensor/Transmitter on the vehicle. The SKREEM
TPMS does not use a magnet to relearn, it automat-
ically learns while driving after a SKREEM or a
Sensor/Transmitter has been replaced.
3.15.9.1
TRAINING THE SKREEM
If a Sensor/Transmitter is replaced, the vehicle
has to be parked for at least 15 minutes for the
system to be ready to learn the new Sensor/
Transmitter ID code. The vehicle then must be
driven for a minimum of five minutes with a mini-
mum continuous speed above 13 mph (20 km/h).
The system will learn the new Sensor/Transmitter
and clear the DTC’s automatically. The Sensor/
Transmitters are programmed at the assembly
plant in this clockwise orientation:
Sensor/Transmitter 1 = Left Front
Sensor/Transmitter 2 = Right Front
Sensor/Transmitter 3 = Right Rear
Sensor/Transmitter 4 = Left Rear
33
GENERAL INFORMATION