Abs Indicator Description; Operation; Diagnosis And Testing - Abs Indicator - Chrysler Vehicle User Manual

8J - 20 INSTRUMENT CLUSTER
ABS INDICATOR
DESCRIPTION
An Antilock Brake System (ABS) indicator is stan-
dard equipment on all instrument clusters. However,
this indicator is only functional on vehicles equipped
with the ABS option. The ABS indicator is located
near the lower edge of the instrument cluster, to the
left of center. The ABS indicator consists of a stencil-
like cutout of the International Control and Display
Symbol icon for "Failure of Anti-lock Braking Sys-
tem" in the opaque layer of the instrument cluster
overlay. The dark outer layer of the overlay prevents
the indicator from being clearly visible when it is not
illuminated. An amber Light Emitting Diode (LED)
behind the cutout in the opaque layer of the overlay
causes the icon to appear in amber through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by the LED, which
is soldered onto the instrument cluster electronic cir-
cuit board. The ABS indicator is serviced as a unit
with the instrument cluster.

OPERATION

The ABS indicator gives an indication to the vehi-
cle operator when the ABS system is faulty or inop-
erative. This indicator is hard wired on the
instrument cluster electronic circuit board, and is
completely controlled by the Controller Antilock
Brake (CAB). The ABS indicator Light Emitting
Diode (LED) receives battery current on the instru-
ment cluster electronic circuit board through the
fused ignition switch output (run-start) circuit when-
ever the ignition switch is in the On or Start posi-
tions; therefore, the LED will always be off when the
ignition switch is in any position except On or Start.
The LED only illuminates when it is provided a path
to ground by the CAB through the CAB relay in the
Power Distribution Center (PDC). The CAB will turn
on the ABS indicator for the following reasons:
• Bulb Test - Each time the ignition switch is
turned to the On position the ABS indicator is illu-
minated by the cluster for about two seconds as a
bulb test.
• ABS Self-Test Fault - Each time the CAB
detects a fault in a monitored ABS circuit, the ABS
indicator will be illuminated. The indicator remains
illuminated until the fault condition is corrected, or
until the ignition switch is turned to the Off position,
whichever occurs first.
• ABS Diagnostic Test - The ABS indicator is
blinked on and off by the CAB during the perfor-
mance of the ABS diagnostic tests.
The CAB continually monitors the ABS circuits
and sensors to decide whether the system is in good
operating condition. If the CAB turns the ABS indi-
cator on after the bulb test, it indicates that the CAB
has detected a system malfunction and/or that the
ABS system has become inoperative. The CAB will
store a Diagnostic Trouble Code (DTC) for any mal-
function it detects. (Refer to 5 - BRAKES -
DESCRIPTION). The ABS indicator can be diagnosed
using conventional diagnostic tools and methods.

DIAGNOSIS AND TESTING - ABS INDICATOR

The diagnosis found here addresses an inoperative
Antilock Brake System (ABS) indicator condition. If
there are problems with several indicators in the
instrument cluster, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). If the ABS indicator stays on with the ignition
switch in the On position or comes on and stays on
while driving, proceed to the diagnosis for the ABS
brake system. (Refer to 5 - BRAKES - DIAGNOSIS
AND TESTING). If no ABS problem is found, the fol-
lowing procedure will help to locate a short or open
in the ABS warning indicator driver circuit. Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the instrument cluster from the
instrument panel. Disconnect the instrument panel
wire harness connector (Connector C2) for the instru-
ment cluster from the connector receptacle on the
back of the cluster housing. Reconnect the battery
negative cable. Turn the ignition switch to the On
position and within about two seconds check for con-
tinuity between the ABS warning indicator driver cir-
cuit cavity of the instrument panel wire harness
connector (Connector C2) for the instrument cluster
and a good ground. There should be continuity for
about two seconds after ignition On, and then an
PRECAUTIONS COULD
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