Dodge ZB 2005, Service Manual

Page: 292 / 1873

AIRBAG INDICATOR
DESCRIPTION
An airbag indicator is standard equipment on all
instrument clusters. However, the instrument cluster
can be programmed to disable this indicator on vehi-
cles that are not equipped with the airbag system,
which is not available in some markets. The airbag
indicator is located in the Information Center area of
the instrument cluster, to the left of center. The air-
bag indicator consists of a symbol 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. A red Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the AIRBAG tell-
tale to appear in red through the translucent outer
layer of the overlay when the indicator is illuminated
from behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The air-
bag indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The airbag indicator gives an indication to the
vehicle operator when the airbag system is faulty or
inoperative. The airbag indicator is controlled by a
transistor on the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Occupant
Restraint Controller (ORC) over the Programmable
Communications Interface (PCI) data bus. The airbag
indicator Light Emitting Diode (LED) is completely
controlled by the instrument cluster logic circuit, and
that logic will only allow this indicator to operate
when the instrument cluster receives a battery cur-
rent input on the fused ignition switch output (RUN)
circuit. Therefore, the LED will always be off when
the ignition switch is in any position except ON. The
LED only illuminates when it is provided a path to
ground by the instrument cluster transistor. The
instrument cluster will turn on the airbag indicator
for the following reasons:
•
Bulb Test - Each time the ignition switch is
turned to the ON position the airbag indicator is illu-
minated for about seven seconds. The first two sec-
onds is the cluster bulb test function, and the
remainder is the ORC bulb test function.
•
ORC Lamp-On Message - Each time the clus-
ter receives a lamp-on message from the ORC, the
airbag indicator will be illuminated. The indicator
remains illuminated for about six to eight seconds or
until the cluster receives a lamp-off message from
the ORC, whichever is longer.
•
Communication Error - If the cluster receives
no airbag messages for ten consecutive seconds, the
airbag indicator is illuminated. The indicator
remains illuminated until the cluster receives a sin-
gle lamp-off message from the ORC.
•
Actuator Test - Each time the cluster is put
through the actuator test, the airbag indicator will be
turned ON, then OFF again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry. The actuator
test illumination of the airbag indicator is a function
of the instrument cluster.
The ORC continually monitors the airbag system
circuits and sensors to decide whether the system is
in good operating condition. The ORC then sends the
proper LAMP-ON or LAMP-OFF messages to the
instrument cluster. If the ORC sends a LAMP-ON
message after the bulb test, it indicates that the
ORC has detected a system malfunction and/or that
the airbags and seat belt tensioners may not deploy
when required, or may deploy when not required.
The ORC will store a Diagnostic Trouble Code (DTC)
for any malfunction it detects. Each time the airbag
indicator fails to illuminate due to an open or short
in the cluster airbag indicator circuit, the cluster
sends a message notifying the ORC of the condition,
the ORC will store a DTC. For proper diagnosis of
the airbag system, the ORC, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the airbag indicator, a DRBIII
t
scan tool
and the proper Body Diagnostic Procedures manual
must be used.
INSTRUMENT CLUSTER
GAUGE PACK
REMOVAL
Follow all Warnings for airbag component service
(Refer to 8 - ELECTRICAL/RESTRAINTS - WARN-
ING).
(1) Open deck lid.
(2) Remove four bolts to battery compartment
cover and remove cover.
(3) Disconnect and isolate the battery negative
cable.
(4) Wait two minutes for the airbag system reserve
capacitor to discharge before beginning any airbag
system or instrument panel component service.
(5) Remove center console (Refer to 23 - BODY/IN-
TERIOR/CENTER CONSOLE - REMOVAL).
(6) Remove six screws and disconnect three electri-
cal connectors to instrument panel center bezel and
remove bezel from vehicle.
(7) Remove five screws and two electrical connec-
tors to the instrument cluster gauge pack and
remove from panel (Fig. 1).
ZB
INSTRUMENT CLUSTER 8J - 5