(3) Continue to hold both buttons depressed until
the EVIC software version information is displayed,
then release both buttons.
(4) Following completion of these tests, the EVIC
module will display one of the following messages:
a.
Pass Self Test - Momentarily depress and
release the Reset button to return to the compass/
thermometer/trip computer display mode. The EVIC
module is working properly.
b.
Failed Self Test - The EVIC module has an
internal failure. The EVIC module is faulty and must
be replaced.
c.
Failed J1850 Communication - The EVIC
module
is
not
receiving
proper
message
input
through the PCI data bus. This can result from one
or more faulty electronic modules in the vehicle, or
from a faulty PCI data bus. The use of a DRB scan
tool and the proper Diagnostic Procedures manual
are required for further diagnosis.
NOTE: If the compass functions, but accuracy is
suspect, it may be necessary to perform a variation
adjustment. This procedure allows the compass
unit to accommodate variations in the earth’s mag-
netic field strength, based on geographic location.
Refer to Compass Variation Adjustment in the Ser-
vice Procedures section of this group.
NOTE: If the compass reading displays dashes,
and only “CAL” appears in the display, demagnetiz-
ing may be necessary to remove excessive residual
magnetic fields from the vehicle. Refer to Compass
Demagnetizing in the Service Procedures section of
this group.
UNIVERSAL GARAGE DOOR OPENER
If the Universal Garage Door Opener (UGDO) is
inoperative, but the Electronic Vehicle Information
Center (EVIC) is operating normally, see the owner’s
manual in the vehicle glove box for instructions on
training the UGDO. Retrain the UGDO with a
known good transmitter as instructed in the owner’s
manual and test the UGDO operation again. If the
unit is still inoperative, replace the faulty UGDO and
EVIC module as a unit. If both the UGDO and the
EVIC module are inoperative, refer to Electronic
Vehicle Information Center in the Diagnosis and
Testing section of this group for further diagnosis.
For complete circuit diagrams, refer to Overhead
Console in the Contents of Group 8W - Wiring Dia-
grams.
AMBIENT TEMPERATURE SENSOR
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Body Control Module (BCM), the Programmable
Communications Interface (PCI) data bus, and a por-
tion of the Electronic Vehicle Information Center
(EVIC) module. If any portion of the ambient temper-
ature sensor circuit fails, the BCM will self-diagnose
the circuit. A “Short Circuit” message will appear in
the EVIC display in place of the temperature when
the sensor is exposed to temperatures above 55° C
(131° F), or if the sensor circuit is shorted. An “Open
Circuit” message will appear in the EVIC display in
place of the temperature when the sensor is exposed
to temperatures below –40° C (–40° F), or if the sen-
sor circuit is open.
The ambient temperature sensor circuit can also be
diagnosed using the following Sensor Test, and Sen-
sor Circuit Test. If the temperature sensor and cir-
cuit are confirmed to be OK, but the temperature
display is inoperative or incorrect, refer to Elec-
tronic Vehicle Information Center in the Diagno-
sis and Testing section of this group. For complete
circuit diagrams, refer to Body Control Module in
the Contents of Group 8W - Wiring Diagrams.
SENSOR TEST
(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 –40° C (–40° F), the sensor resis-
tance is 336 kilohms. At 55° C (140° F), the sensor
resistance is 2.488 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Sensor Circuit Test in the Diagnosis and Testing
section of this group. If not OK, replace the faulty
ambient temperature sensor.
SENSOR CIRCUIT TEST
(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 and the 22-way Body Control Module
(BCM) wire harness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the 22-way BCM wire harness con-
nector. There should be continuity. If OK, go to Step
4. If not OK, repair the open sensor return circuit or
ambient temperature sensor signal circuit to the
ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
8V - 6
OVERHEAD CONSOLE SYSTEMS
WJ
DIAGNOSIS AND TESTING (Continued)