Turn Signal Indicator Lamps; Upshift Indicator Lamp; Diagnosis And Testing - Jeep Wrangler 1997 Manual

8E - 8 INSTRUMENT PANEL SYSTEMS
DESCRIPTION AND OPERATION (Continued)
seconds after the ignition switch is turned to the On
position, if the instrument cluster circuitry has
detected an inoperative airbag warning lamp circuit
during the bulb test sequence, it will flash the seat
belt reminder lamp on and off for about twenty sec-
onds . If the seat belt reminder lamp flashes longer
than twenty seconds, or flashes at any time other
than about twenty seconds after the initial igni-
tion-on sequence, it indicates an airbag system fault
has been detected and that the airbag indicator lamp
is inoperative .
Refer to Group 8U - Chime/Buzzer Warning Sys-
tems for more information on the seat belt switch.
Refer to Group 8M - Passive Restraint Systems for
more information on the airbag system .
TURN SIGNAL INDICATOR LAMPS
The left and right turn signal indicator lamps give
an indication when the turn signal circuits are acti-
vated . The lamps are completely controlled by a
hard-wired input to the instrument cluster from the
turn signal and hazard warning (multi-function)
switches .
The lamps are grounded at all times and receive
battery feed through the contacts of the multifunc-
tion switch when the turn signal lever (multi-func-
tion switch stalk) or hazard warning button are
actuated to the On position . The instrument cluster
circuitry does not perform a bulb test of these lamps .
Refer to Group 8J - Turn Signal and Hazard Warning
Systems for more information .
UPSHIFT INDICATOR LAMP
Vehicles equipped with a manual transmission
have an upshift indicator lamp. The upshift indicator
lamp gives an indication when the driver should shift
to the next highest gear for the best fuel economy.
The lamp is turned on by the instrument cluster cir-
cuitry for about three seconds when the ignition
switch is turned to the On position as a bulb test .
After the bulb test, the lamp is controlled by the
instrument cluster circuitry based upon a message
received from the Powertrain Control Module (PCM)
on the Chrysler Collision Detection (CCD) data bus .
The PCM uses inputs from many sensors and its
internal programming to decide whether the engine
speed and load conditions are proper for a transmis-
sion upshift . The PCM then sends the proper mes-
sage to the instrument cluster on the CCD data bus
to turn the lamp on or off. The PCM will send a
lamp-off message three to five seconds after a
lamp-on message, if an upshift is not performed . The
lamp will then remain off until the vehicle stops
accelerating and is brought back into the range of
lamp operation, or until the transmission is shifted
into another gear. Refer to Group 14 - Fuel Systems
TJ
for more information on the PCM and the PCM
inputs .
DIAGNOSIS AND TESTING
INSTRUMENT CLUSTER
If all of the gauges and/or indicator lamps are inop-
erative, review the following Preliminary Diagnosis .
If an individual gauge or CCD data bus message-con-
trolled indicator lamp is inoperative, go directly to
the Actuator Test. If an individual hard-wired indica-
tor lamp is inoperative, go directly to the diagnosis
for that lamp. For circuit descriptions and diagrams,
refer to 8W-40 - Instrument Cluster in Group 8W -
Wiring Diagrams .
WARNING : ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER
TO
GROUP
8M
-
PASSIVE
RESTRAINT SYSTEMS BEFORE
ATTEMPTING
STEERING WHEEL, STEERING COLUMN,
OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE . FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
PRELIMINARY DIAGNOSIS
(1) If the indicator lamps operate, but none of the
gauges operate, go to Step 2. If all of the gauges and
the data bus message-controlled indicator lamps are
inoperative, go to Step 5.
(2) Check the Ignition-Off Draw (IOD) fuse in the
Power Distribution Center (PDC) . If OK, go to Step
3 . If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(3) Check for battery voltage at the IOD fuse in
the PDC . If OK, go to Step 4. If not OK, repair the
open circuit as required .
(4) Remove the instrument cluster as described in
this group. Check for battery voltage at the fused
B(+) circuit cavity of the left (black) cluster connec-
tor. If OK, go to the Actuator Test. If not OK, repair
the open circuit to the IOD fuse as required .
(5) Check the fuse in the fuseblock module . If OK,
go to Step 6. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(6) Turn the ignition switch to the On position and
check for battery voltage at the fuse in the fuseblock
module . If OK, go to Step 7. If not OK, repair the
open circuit to the ignition switch as required .
(7) With the ignition switch still in the On posi-
tion, set the parking brake. The brake warning lamp
should light . If OK, go to Step 8. If not OK, go to
Step 9.