INSTRUMENT CLUSTER
TABLE OF CONTENTS
page page
INSTRUMENT CLUSTER
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - SELF-
DIAGNOSTICS.........................2
DIAGNOSIS AND TESTING - CLUSTER
DIAGNOSIS...........................3REMOVAL.............................11
INSTALLATION.........................11
CLUSTER LENS
REMOVAL.............................11
INSTALLATION.........................11
INSTRUMENT CLUSTER
DESCRIPTION
The instrumentation gauges are contained in a
subdial assembly within the instrument cluster. The
individual gauges are not serviceable. If one of the
cluster gauges becomes faulty, the entire cluster
would require replacement.
The Mechanical Instrument Cluster (MIC) with a
tachometer is equipped with a electronic vacuum flu-
orescent transmission range indicator (PRND3L),
odometer, and trip odometer display.
The MIC without a tachometer is equipped with a
Light Emitting Diode (LED) transmission range indi-
cator (PRND3L) and a vacuum fluorescent odometer
display.
The MIC is equipped with the following warning
lamps.
²Lift Gate Ajar
²Low Fuel Level
²Low Windshield Washer Fluid Level
²Cruise
²Battery Voltage
²Fasten Seat Belt
²Door Ajar
²Coolant Temperature
²Anti-Lock Brake
²Brake
²Oil Pressure
²MIL (Malfunction Indicator Lamp)
²VTSS/SKIS Indicator
²Airbag
²Traction Control
²Autostick
Export Only- uses a message center that displays
the following telltales:
²Turns Signals
²High Beam
²Tire Pressure Monitoring (TPM)²Glow Plug (Export Only)
²Supplemental Cabin Heater (Export Only)WATER IN FUEL LAMP - EXPORT
The Water In Fuel Lamp is located in the message
center. When moisture is found within the fuel sys-
tem, the sensor sends a message via the PCI data
bus to the instrument cluster. The MIC illuminates
the bulb in the message center, The sensor is located
underneath the vehicle, directly above the rear axle.
The sensor is housed within the fuel filter/water sep-
arator assembly cover. The sensor is not serviced sep-
arately. If found defective, the entire assembly cover
must be replaced.
OPERATION
Refer to the vehicle Owner's Manual for operation
instructions and conditions for the Instrument Clus-
ter Gauges.
WATER IN FUEL LAMP/SENSOR - EXPORT
The Water In Fuel Sensor is a resistive type
switch. It is calibrated to sense the different resis-
tance between diesel fuel and water. When water
enters the fuel system, it is caught in the bottom of
the fuel filter/water separator assembly, where the
sensor is located. Water has less resistance than die-
sel fuel. The sensor then sends a PCI data bus mes-
sage to the instrument cluster to illuminate the
lamp.
If the lamp is inoperative, perform the self diag-
nostic test on the instrument cluster to check the
lamp operation before continuing diagnosis.
RSINSTRUMENT CLUSTER8J-1
RESTRAINTS
TABLE OF CONTENTS
page page
RESTRAINTS
DESCRIPTION..........................2
OPERATION............................4
WARNING
WARNINGS...........................5
DIAGNOSIS AND TESTING - AIRBAG SYSTEM . 6
STANDARD PROCEDURE
STANDARD PROCEDURE - HANDLING
AIRBAGS.............................6
STANDARD PROCEDURE - SERVICE
AFTER AN AIRBAG DEPLOYMENT.........7
BELT TENSION SENSOR
DESCRIPTION..........................8
OPERATION............................9
CHILD RESTRAINT ANCHOR
DESCRIPTION..........................9
OPERATION...........................10
CLOCKSPRING
DESCRIPTION.........................10
OPERATION...........................11
STANDARD PROCEDURE - CLOCKSPRING
CENTERING.........................11
REMOVAL.............................12
INSTALLATION.........................12
CURTAIN AIRBAG
DESCRIPTION.........................12
OPERATION...........................13
REMOVAL.............................14
INSTALLATION.........................16
DRIVER AIRBAG
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................17
INSTALLATION.........................18
IMPACT SENSOR
DESCRIPTION.........................18
REMOVAL.............................19
INSTALLATION.........................21
KNEE BLOCKER AIRBAG
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................23
INSTALLATION.........................23
OCCUPANT CLASSIFICATION MODULE
DESCRIPTION.........................25
OPERATION...........................25
REMOVAL.............................26
INSTALLATION.........................26OCCUPANT RESTRAINT CONTROLLER
DESCRIPTION.........................27
OPERATION...........................28
REMOVAL.............................29
INSTALLATION.........................29
PASSENGER AIRBAG
DESCRIPTION.........................30
OPERATION...........................30
REMOVAL.............................30
INSTALLATION.........................32
PASSENGER AIRBAG DISABLED INDICATOR
DESCRIPTION.........................33
OPERATION...........................33
REMOVAL.............................34
INSTALLATION.........................34
SEAT BELT BUCKLE - FRONT INBOARD
REMOVAL.............................35
INSTALLATION.........................35
SEAT BELT BUCKLE - FIRST ROW INBOARD -
QUAD BUCKET
REMOVAL.............................35
INSTALLATION.........................36
SEAT BELT BUCKLE - FIRST ROW - BENCH
REMOVAL.............................36
INSTALLATION.........................37
SEAT BELT BUCKLE - SECOND ROW
INBOARD - 50/50 BENCH
REMOVAL.............................37
INSTALLATION.........................38
SEAT BELT HEIGHT ADJUSTER-BOR
C-PILLAR
REMOVAL.............................38
INSTALLATION.........................38
SEAT BELT HEIGHT ADJUSTER KNOB
REMOVAL.............................38
INSTALLATION.........................38
SEAT BELT & RETRACTOR - OUTBOARD -
FRONT
REMOVAL.............................38
INSTALLATION.........................39
SEAT BELT & RETRACTOR - FIRST ROW -
OUTBOARD
REMOVAL.............................39
INSTALLATION.........................40
SEAT BELT BUCKLE - SECOND ROW - THREE
PASSENGER BENCH
REMOVAL.............................40
INSTALLATION.........................40
RSRESTRAINTS8O-1
²Occupant Classification System- These
vehicles also include an Occupant Classification Sys-
tem (OCS) with components that are located on or in
the passenger front seat cushion. These components
include an Occupant Classification Module (OCM)
and a seat weight bladder and pressure sensor
assembly. In addition, this system includes a belt
tension sensor integral to the lower anchor of the
passenger side front seat belt. Vehicles equipped with
the OCS can be readily identified by a Passenger Air-
bag Disabled (PAD) indicator (Fig. 1) located in the
center stack on the instrument panel above HVAC
control head and radio.
²Curtain Airbags- Curtain airbags are avail-
able for this model when it is also equipped with
dual front airbags. This airbag system is a passive,
inflatable, Supplemental Restraint System (SRS) and
vehicles with this equipment can be readily identified
by a molded identification trim button with the ªSRS
- AIRBAGº logo (Fig. 2) located on the headliner
above each B-pillar.
This vehicle is equipped with a Frontal Impact Air-
bag System, which utilizes the driver/passenger air-
bags, driver knee blocker airbag, and seat belt
tensioners. This system is designed to protect occu-
pants in the event of a front impact collision. These
airbags and seat belt tensioners are all serviceable
parts. If these pyrotechnics are deployed or defective,
they must be replaced, as well as the OccupantRestraint Controller (ORC) must be diagnosed follow-
ing procedures outlined in the diagnostic information.
The Driver and Passenger Airbag System was
designed to reduce the likelihood of injury or death
in frontal collisions. Each separate system is supple-
mental (Fig. 2) orPassiveto the primary restraint
device, which are the seat belts.
²Airbag Indicator- The airbag indicator is inte-
gral to the Instrument Cluster, which is located on
the instrument panel in front of the driver.
²Belt Tension Sensor- Vehicles equipped with
the Occupant Classification System (OCS) include a
belt tension sensor. This sensor is integral to the pas-
senger side front seat belt lower anchor which is
secured to the floor, out board and rear of the front
passenger seat. -.....concealed beneath an access cover
on the seat belt assembly.
²Clockspring- The clockspring is located near
the top of the steering column, directly beneath the
steering wheel (Fig. 3).
²Curtain Airbag- A side curtain airbag is
located on each inside roof side rail above the head-
liner, and extends from the A-pillar to just beyond
the D-pillar.
²Driver Airbag- The driver airbag is located in
the center of the steering wheel, beneath the driver
airbag trim cover (Fig. 3).
²Front Impact Sensor- Two front impact sen-
sors are used on vehicles equipped with dual front
airbags, one left side and one right side. The sensors
are located on the rail tips, rearward of the bumper
attachments.
²Knee Blocker Airbag- The driver knee blocker
airbag is secured to the instrument panel behind the
steering column opening cover (Fig. 3).
Fig. 1 PAD INDICATOR
Fig. 2 SRS LOGO
Fig. 3 AIRBAG COMPONENT LOCATION -
INSTRUMENT PANEL
1 - DRIVER AIRBAG
2 - PASSENGER AIRBAG DISABLED (PAD) INDICATOR
3 - PASSENGER AIRBAG
4 - OCCUPANT RESTRAINT CONTROLLER (ORC)
5 - KNEE BLOCKER AIRBAG
RSRESTRAINTS8O-3
RESTRAINTS (Continued)
driver and the front seat passenger to the structure
of the instrument panel (Refer to 8 - ELECTRICAL/
RESTRAINTS/KNEE BLOCKER AIRBAG -
DESCRIPTION). The seat belt tensioners remove the
slack from the front seat belts to provide further
assurance that the driver and front seat passenger
are properly positioned and restrained for an airbag
deployment.
When the ORC monitors a problem in any of the
dual front airbag system circuits or components,
including the seat belt tensioners, it stores a Diag-
nostic Trouble Code (DTC) in its memory and sends
an electronic message to the EMIC to turn on the
airbag indicator. Proper testing of the supplemental
restraint system components, the Programmable
Communications Interface (PCI) data bus, the elec-
tronic message inputs to and outputs from the EMIC
or the ORC, as well as the retrieval or erasure of a
DTC from the ORC or the EMIC requires the use of
a scan tool. Refer to the appropriate diagnostic infor-
mation.
OCCUPANT CLASSIFICATION SYSTEM
The Occupant Classification System (OCS) auto-
matically suppresses or enables passenger airbag and
seat belt tensioner operation based upon whether or
not the passenger side front seat is occupied and, if
the seat is occupied, classifies the size of the occu-
pant and whether the seat is occupied by a child
seat.
The OCS has an Occupant Classification Module
(OCM) that monitors inputs from the seat weight
bladder pressure sensor under the passenger side
front seat cushion and from the belt tension sensor
on the passenger side front seat belt lower anchor.
Based upon those inputs the microprocessor within
the OCM classifies the occupant of the passenger
side front seat. The OCM then sends electronic occu-
pant classification messages to the ORC. The micro-
processor and programming of the ORC uses these
occupant classification messages to determine
whether to enable or disable the deployment circuits
for the passenger airbag and seat belt tensioner.
The OCS electrical circuits and components are
continuously monitored by the OCM, and the OCM is
continuously monitored by the ORC. A passenger air-
bag ON/OFF indicator is located in the instrument
panel center stack area. This indicator receives bat-
tery current whenever the ignition switch is in the
ON or START positions, and illuminates only when
the ORC pulls the indicator control circuit to ground.
The indicator illuminates for about seven seconds as
a bulb test each time the ignition switch is turned to
the ON or START positions. Following the bulb test,
the indicator is turned ON or OFF by the ORC based
upon the electronic occupant classification messagesreceived from the OCM. This indicator is illuminated
whenever the passenger airbag and seat belt ten-
sioner operation has been suppressed, and is turned
OFF whenever they are enabled or when the passen-
ger seat is classified as empty.
When the OCM monitors a problem in any of the
OCS circuits or components, it stores a fault code or
DTC in its memory circuit and sends an electronic
message to the ORC. The ORC then sends an elec-
tronic message to the EMIC to turn ON the airbag
indicator. If for any reason the OCM is unable to
classify the occupant it sends an electronic message
to the ORC, and the ORC suppresses passenger air-
bag and seat belt tensioner operation. Proper testing
of the OCS components, the Programmable Commu-
nications Interface (PCI) data bus, the electronic
message inputs to and outputs from the OCM, the
EMIC or the ORC, as well as the retrieval or erasure
of a DTC's, requires the use of a scan tool. Refer to
the appropriate diagnostic information.
WARNING
WARNINGS
Disconnect and isolate the battery negative
cable before beginning any airbag system com-
ponent diagnosis, testing, removal, or installa-
tion procedures. Allow system capacitor to
discharge for two minutes before beginning any
component testing or service. This will disable
the airbag system. Failure to disconnect the
battery negative cable may result in accidental
airbag deployment, personal injury, or death.
Do not place an intact undeployed airbag
face down on a solid surface. The airbag will
propel into the air if accidentally deployed and
may result in personal injury or death.
When carrying or handling an undeployed
airbag, the trim side (face) of the airbag should
be pointing towards the body to minimize pos-
sibility of injury if accidental deployment
occurs. Failure to do this may result in per-
sonal injury or death.
Replace airbag system components with
Mopartreplacement parts. Substitute parts
may appear interchangeable, but internal dif-
ferences may result in inferior occupant protec-
tion. Failure to do so may result in occupant
personal injury or death.
Wear safety glasses, rubber gloves, and long
sleeved clothing when cleaning powder residue
from vehicle after airbag deployment. Sodium
hydroxide powder residue emitted from a
deployed airbag can cause skin irritation.
Flush affected area with cool water if irritation
is experienced. If nasal or throat irritation is
RSRESTRAINTS8O-5
RESTRAINTS (Continued)
UNDEPLOYED AIRBAG
WARNING: The airbags must be stored in its origi-
nal special container until used for service. At no
time should a source of electricity be permitted
near the inflator on the back of an airbag. When
carrying or handling an undeployed airbag, the trim
side of the airbag should be pointing toward the
body to minimize the possibility of personal injury
or death if accidental deployment occurs. Do not
place undeployed airbag face down on a solid sur-
face, the airbag will propel into the air if accidental
deployment occurs.
STANDARD PROCEDURE - SERVICE AFTER AN
AIRBAG DEPLOYMENT
DRIVER AIRBAG
After a Driver Airbag has been deployed due to a
collision, the followingMUSTbe replaced:
²Driver Airbag
²Clockspring Assembly
²Steering Wheel
²Complete Steering Column Assembly w/Lower
Steering Column Coupler
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
PASSENGER AIRBAG
After a Passenger Airbag has been deployed due to
a collision. the followingMUSTbe replaced:
²Passenger Airbag
²Instrument Panel and Pad Assembly
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
KNEE BLOCKER AIRBAG
After a Knee Blocker Airbag has been deployed due
to a collision. the followingMUSTbe replaced:
²Knee Blocker Airbag
²Instrument Panel and Pad Assembly
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
CURTAIN AIRBAG
After a Curtain Airbag has been deployed due to a
collision. the followingMUSTbe replaced:
²Curtain Airbag Assembly
²Headliner
²A, B, and C-Pillar Trim on deployed side.
All other airbag and vehicle components should be
closely inspected following any airbag deployment,
and should be replaced when visible damage is
incurred.
WARNING: Do not connect the battery negative
cable (Refer to 8 - ELECTRICAL/RESTRAINTS -
DIAGNOSIS AND TESTING - AIRBAG SYSTEM). Per-
sonal injury or death may result if the system test
is not performed first.
OCCUPANT CLASSIFICATION SYSTEM (OCS)
After an impact event, either front, rear, or side,
the OCS system components need to be inspected
and replaced if found to be damaged.
This includes:
²Belt Tension Sensor
²Occupant Classification Module (OCM)
²Passenger Airbag ON/Off Indicator
²Seat Weight Bladder and Sensor
RSRESTRAINTS8O-7
RESTRAINTS (Continued)
anchor. The OCM then monitors the return voltage
from each of the sensors. The bladder pressure sen-
sor input allows the OCM to determine whether the
passenger front seat is occupied and the relative size
of the occupant by providing a weight-sensing refer-
ence to the load on the seat cushion. The belt tension
sensor provides an additional logic input to the OCM
microprocessor that allows it to distinguish between
the lower seat belt cinch loads of a belted occupant
and the higher loads associated with a belted child
seat.
Pre-programmed decision algorithms and OCS cal-
ibration allow the OCM microprocessor to determine
when the seat cushion load as signaled by the blad-
der pressure sensor and the seat belt cinch load as
signaled by the belt tension sensor indicate that pas-
senger airbag protection is appropriate. When the
programmed conditions are met, the OCM sends the
proper electronic occupant classification messages
over the PCI data bus to the Occupant Restraint
Controller (ORC), and the ORC enables or disables
the deployment circuits for the passenger front sup-
plemental restraints. The ORC also provides a con-
trol output for the Passenger Airbag Disabled (PAD)
indicator in the instrument panel center stack, based
upon the electronic occupant classification messages
it receives from the OCM.
The OCM microprocessor continuously monitors all
of the OCS electrical circuits and components to
determine the system readiness. If the OCM detects
a monitored system fault, it sets an active and stored
Diagnostic Trouble Code (DTC) and sends the appro-
priate electronic messages to the ORC over the PCI
data bus. Then the ORC sets a DTC and sends mes-
sages to control the airbag indicator operation
accordingly. An active fault only remains for the
duration of the fault, or in some cases for the dura-
tion of the current ignition switch cycle, while a
stored fault causes a DTC to be stored in memory by
the OCM and the ORC. For some DTC's, if a fault
does not recur for a number of ignition cycles, the
OCM will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
The OCM receives battery current from an IPM
high side driver (Run/Start). The OCM receives
ground through a ground circuit of the body wire
harness, which it shares with the ORC. These con-
nections allow the OCM to be operational whenever
the ignition switch is in the Start or ON positions.
To diagnose and test the OCS, use a scan tool and
the appropriate diagnostic information.
REMOVAL
Once any of the original factory-installed compo-
nents except the Occupant Classification Module(OCM) have been replaced with the service replace-
ment package components, the OCM can only be ser-
viced by replacing the entire passenger front seat
cushion unit with another complete service replace-
ment package (Refer to 23 - BODY/SEATS/SEAT
CUSHION - FRONT - REMOVAL).
WARNING: Never replace both the Occupant
Restraint Controller (ORC) and the Occupant Clas-
sification Module (OCM) at the same time. If both
require replacement, replace one, then perform the
Airbag System test (Refer to 8 - ELECTRICAL/RE-
STRAINTS - DIAGNOSIS AND TESTING - AIRBAG
SYSTEM) before replacing the other. Both the ORC
and the OCM store Occupant Classification System
(OCS) calibration data, which they transfer to one
another when one of them is replaced. If both are
replaced at the same time, an irreversible fault will
be set in both modules and the OCS may malfunc-
tion and result in personal injury or death.
(1) Disconnect and isolate the battery negative
cable.
(2)
WARNING: Wait two minutes for the airbag system
reserve capacitor to discharge before beginning
any airbag system or component service. Failure to
do so may result in accidental airbag deployment,
personal injury or death.
(3) Reach under the front edge of the passenger
side front seat cushion to access and remove the lock
pin from the connector lock tower on the Occupant
Classification Module (OCM) (Fig. 36).
(4) Disconnect the passenger front seat wire har-
ness connector for the OCM.
(5) Remove the two screws that secure the OCM to
the OCM bracket.
(6) Remove the OCM from under the passenger
front seat.
INSTALLATION
WARNING: To avoid personal injury or death on
vehicles equipped with the Occupant Classification
System (OCS), only the Occupant Classification
Module (OCM) and the seat cushion trim may be
serviced separately. All other components of the
passenger front seat cushion must be serviced only
as a complete factory-calibrated, assembled and
tamper-evident service replacement package.
Once any of the original factory-installed compo-
nents except the OCM have been replaced with the
service replacement package components, the OCM
can only be serviced by replacing the entire passen-
8O - 26 RESTRAINTSRS
OCCUPANT CLASSIFICATION MODULE (Continued)
The ORC is secured with screws to a stamped steel
mounting bracket welded onto the top of the floor
panel transmission tunnel just behind and under-
neath the instrument panel center stack in the pas-
senger compartment of the vehicle (Fig. 38).
Concealed within a hollow in the center of the die
cast aluminum ORC housing is the electronic cir-
cuitry of the ORC which includes a microprocessor,
an electronic impact sensor, an electronic safing sen-
sor, and an energy storage capacitor. A stamped
metal cover plate is secured to the bottom of the
ORC housing with four screws to enclose and protect
the internal electronic circuitry and components.
An arrow printed on the label on the top of the
ORC housing provides a visual verification of the
proper orientation of the unit, and should always be
pointed toward the front of the vehicle. The ORC
housing has integral mounting flanges. the ORC has
two molded plastic electrical connectors that exits the
right facing side of the ORC housing. These terminal
pins connect the ORC to the vehicle electrical system.
The impact sensor and safing sensor internal to
the ORC are calibrated for the specific vehicle, and
are only serviced as a unit with the ORC. In addi-
tion, there are unique versions of the ORC for vehi-
cles with or without curtain airbags. The ORC cannot
be repaired or adjusted and, if damaged or faulty, it
must be replaced.
OPERATION
The microprocessor in the Occupant Restraint Con-
troller (ORC) contains the supplemental restraint
system logic circuits and controls all of the supple-
mental restraint system components. The ORC uses
On-Board Diagnostics (OBD) and can communicatewith other electronic modules in the vehicle as well
as with the diagnostic scan tool using the Program-
mable Communication Interface (PCI) data bus. This
method of communication is used for control of the
airbag indicator in the ElectroMechanical Instrument
Cluster (EMIC) and for supplemental restraint sys-
tem diagnosis and testing through the 16-way Data
Link Connector (DLC) located on the driver side
lower edge of the instrument panel.
The ORC microprocessor continuously monitors all
of the supplemental restraint system electrical cir-
cuits to determine the system readiness. If the ORC
detects a monitored system fault, it sets an active
and stored Diagnostic Trouble Code (DTC) and sends
electronic messages to the EMIC over the PCI data
bus to turn on the airbag indicator. An active fault
only remains for the duration of the fault, or in some
cases for the duration of the current ignition switch
cycle, while a stored fault causes a DTC to be stored
in memory by the ORC. For some DTC's, if a fault
does not recur for a number of ignition cycles, the
ORC will automatically erase the stored DTC. For
other internal faults, the stored DTC is latched for-
ever.
On models equipped with the Occupant Classifica-
tion System (OCS), the ORC communicates with the
Occupant Classification Module (OCM) over the PCI
data bus. The ORC will internally disable the pas-
senger airbag and seat belt tensioner deployment cir-
cuits if the OCM detects that the passenger side
front seat is unoccupied or that it is occupied by a
load that is inappropriate for an airbag deployment.
The ORC also provides a control output to the Pas-
senger Airbag Disabled (PAD) indicator through the
passenger airbag indicator driver circuit. The OCM
notifies the ORC when it has detected a monitored
system fault and stored a DTC in its memory for any
faulty OCS component or circuit, then the ORC sets
a DTC and controls the airbag indicator operation
accordingly.
The ORC receives battery current through two cir-
cuits; a fused ignition switch output (RUN) circuit
through a fuse in the Junction Block (JB), and a
fused ignition switch output (RUN/START) circuit
through a second fuse in the JB. The ORC receives
ground through a ground circuit of the instrument
panel wire harness. These connections allow the ORC
to be operational whenever the ignition switch is in
the START or ON positions.
The ORC also contains an energy-storage capacitor.
When the ignition switch is in the START or ON
positions, this capacitor is continually being charged
with enough electrical energy to deploy the front sup-
plemental restraint components for up to one second
following a battery disconnect or failure. The purpose
of the capacitor is to provide backup supplemental
Fig. 38 ORC LOCATION
1 - ORC ELECTRICAL CONNECTORS
2 - ORC
3 - ORC MOUNTING SCREWS
8O - 28 RESTRAINTSRS
OCCUPANT RESTRAINT CONTROLLER (Continued)
restraint system protection in case there is a loss of
battery current supply to the ORC during an impact.
Two sensors are contained within the ORC, an
electronic impact sensor and a safing sensor. The
ORC also monitors inputs from eight remote impact
sensors. Two front impact sensors are located on each
outboard side of the lower radiator support, and
three side impact sensors are located on each side of
the vehicle at the B-pillar, in the lower sliding door
opening in front of the C-pillar, and over the rear
wheel well between the C and D-pillars. The elec-
tronic impact sensors are accelerometers that sense
the rate of vehicle deceleration, which provides veri-
fication of the direction and severity of an impact.
The safing sensor is an electronic accelerometer
sensor within the ORC that provides an additional
logic input to the ORC microprocessor. The safing
sensor is used to verify the need for a supplemental
restraint deployment by detecting impact energy of a
lesser magnitude than that of the primary electronic
impact sensors, and must exceed a safing threshold
in order for the airbags to deploy. Vehicles equipped
with curtain airbags, there is a second safing sensor
within the ORC to provide confirmation to the ORC
microprocessor of side impact forces. This second saf-
ing sensor is a bi-directional unit that detects impact
forces from either side of the vehicle.
Pre-programmed decision algorithms in the ORC
microprocessor determine when the deceleration rate
as signaled by the impact sensors and the safing sen-
sors indicate an impact that is severe enough to
require supplemental restraint system protection
and, based upon the severity of the monitored
impact, determines the level of front airbag deploy-
ment force required for each front seating position.
When the programmed conditions are met, the ORC
sends the proper electrical signals to deploy the dual
multistage front airbags at the programmed force
levels, the front seat belt tensioners and, if the vehi-
cle is so equipped, either curtain airbag. For vehicles
equipped with the OCS, the passenger front airbag
and seat belt tensioner will be deployed by the ORC
only if enabled by the OCM messages (PAD indicator
OFF) at the time of the impact.
To diagnose and test the ORC and all airbag sys-
tem components, use a scan tool and the appropriate
diagnostic information.
REMOVAL
WARNING: Never replace both the Occupant
Restraint Controller (ORC) and the Occupant Clas-
sification Module (OCM) at the same time. If both
require replacement, replace one, then perform the
Airbag System test (Refer to 8 - ELECTRICAL/RE-
STRAINTS - DIAGNOSIS AND TESTING - AIRBAGSYSTEM) before replacing the other. Both the ORC
and the OCM store Occupant Classification System
(OCS) calibration data, which they transfer to one
another when one of them is replaced. If both are
replaced at the same time, an irreversible fault will
be set in both modules and the OCS may malfunc-
tion and result in personal injury or death.
(1) Disconnect and isolate the battery negative
cable.
(2)
WARNING: Wait two minutes for the airbag system
reserve capacitor to discharge before beginning
any airbag system or component service. Failure to
do so may result in accidental airbag deployment,
personal injury or death.
(3) Remove storage bin from instrument panel
(Refer to 23 - BODY/INSTRUMENT PANEL/STOR-
AGE BIN - REMOVAL).
(4) Remove three bolts holding ORC to floor
bracket (Fig. 39).
(5) Disconnect the wire connectors from the ORC
(Fig. 39).
(6) Remove the ORC from vehicle.
INSTALLATION
WARNING: Do not install ORC if mounting location
is deformed or damaged. This will cause the ORC
to be improperly located and could result in occu-
pant personal injury or death.
WARNING: Use correct screws when installing the
ORC.
Fig. 39 ORC - REMOVE/INSTALL
1 - ORC ELECTRICAL CONNECTORS
2 - ORC
3 - ORC MOUNTING SCREWS
RSRESTRAINTS8O-29
OCCUPANT RESTRAINT CONTROLLER (Continued)