Dodge Nitro. Manual — part 241

2 N.m (20 in. lbs.).

3. Reconnect the two seat wire harness connectors to the OCM connector receptacles located on the

forward-facing end of the module. Be certain that the latches on each connector are fully engaged.

4. Do not reconnect the battery negative cable at this time. The Supplemental Restraint System (SRS)

verification test procedure should be performed following service of any SRS component. See
VERIFICATION TEST - SUPPLEMENTAL RESTRAINT SYSTEM.

5. Following successful completion of the SRS verification test procedure, perform the Occupant

Classification System Verification Test using a diagnostic scan tool. Refer to the appropriate diagnostic
procedures.

OCCUPANT RESTRAINT CONTROLLER

DESCRIPTION

OCCUPANT RESTRAINT CONTROLLER

Fig. 49: Identifying Occupant Restraint Controller (ORC), Electrical Connector Receptacle, Label,
Arrow & Mounting Bracket
Courtesy of CHRYSLER LLC

The Occupant Restraint Controller (ORC) (1) is secured with four screws to a molded plastic mounting bracket
(5). The mounting bracket and ORC unit is then secured with two nuts and two screws to a stamped steel
mounting bracket welded onto the top of the floor panel transmission tunnel between the two front seats beneath
the floor console and rearward of the transmission gearshift mechanism in the passenger compartment of the
vehicle. Concealed within a hollow in the center of the molded plastic ORC housing is the electronic circuitry
of the ORC which includes a microprocessor, an electronic impact sensor, an electronic safing sensor, and an
energy storage capacitor. A molded plastic end cover plate with a rubber O-ring seal is secured to the open end
of the ORC housing with two integral latch features to enclose and protect the internal electronic circuitry and
components.

An arrow (4) printed on the label (3) 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 four

2007 Dodge Nitro R/T

2007 RESTRAINTS Service Information - Nitro

integral mounting flanges with metal sleeves to provide crush protection. Two molded plastic electrical
connector receptacles (2) are integral to the end cover plate. These receptacles connect the ORC to the vehicle
electrical system through dedicated take outs and connectors from the instrument panel and the body wire
harnesses.

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. The ORC cannot be repaired or adjusted and, if damaged or ineffective, it must
be replaced as a unit with the molded plastic mounting bracket.

OPERATION

OCCUPANT RESTRAINT CONTROLLER

The microprocessor in the Occupant Restraint Controller (ORC) contains the Supplemental Restraint System
(SRS) logic circuits and controls all of the SRS components. The ORC uses On-Board Diagnostics (OBD) and
can communicate with other electronic modules in the vehicle as well as with the diagnostic scan tool using the
Controller Area Network (CAN) data bus. This method of communication is used for control of the airbag
indicator in the Electro Mechanical Instrument Cluster (EMIC) (also known as the Cab Compartment
Node/CCN) and for SRS diagnosis and testing through the 16-way data link connector located on the driver side
lower edge of the instrument panel. Refer to OPERATION .

The ORC microprocessor continuously monitors all of the SRS electrical circuits 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 CAN 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 DTCs, 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 forever.

On vehicles so equipped, the ORC provides voltage to the seat track position sensors on the inboard passenger
and driver side front seat upper seat tracks. The ORC then monitors return inputs from each of the sensors on
dedicated hard wired data communication circuits. The seat track position sensors provide additional logic
inputs to the ORC microprocessor that allow it to determine the position of the front seat passenger and the
driver relative to the front airbags for determining the force level with which to deploy the multistage front
airbags.

On vehicles equipped with the Occupant Classification System (OCS), the ORC communicates with the
Occupant Classification Module (OCM) over the CAN data bus. The ORC will internally disable the passenger
airbag and seat belt tensioner deployment circuits 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 passenger airbag on/off 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 ineffective OCS component or circuit, then the ORC sets a DTC and controls the airbag
indicator operation accordingly.

The ORC receives battery current through two circuits; a fused ignition switch output (run) circuit through a
fuse in the Totally Integrated Power Module (TIPM), and a fused ignition switch output (run-start) circuit
through a second fuse in the TIPM. The ORC receives ground through a ground circuit and take out of the

2007 Dodge Nitro R/T

2007 RESTRAINTS Service Information - Nitro

instrument panel wire harness. These connections allow the ORC to be operational whenever the ignition switch
is in the START or ON positions. Refer to the appropriate wiring information for additional details.

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 SRS components for up
to one second following a battery disconnect or failure. The purpose of the capacitor is to provide backup SRS
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 two remote front impact sensors located on the back of the right and left ends of the front
end module carrier inboard of the headlamps near the front of the vehicle. The electronic impact sensors are
accelerometers that sense the rate of vehicle deceleration, which provides verification of the direction and
severity of an impact. The ORC also monitors inputs from an internal rollover sensor and four additional remote
impact sensors located on the left and right inner B and C-pillars to control deployment of the side curtain
airbag units.

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 SRS component 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. A second safing sensor within the ORC provides
confirmation to the ORC microprocessor of side impact forces. This second safing 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 sensors indicate an impact that is severe enough to require SRS
protection and, based upon the severity of the monitored impact, determines the level of front airbag
deployment 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 either side curtain airbag unit. For vehicles equipped with the OCS, the
passenger side front airbag and seat belt tensioner will be deployed by the ORC only if enabled by the OCM
messages (passenger airbag on/off indicator OFF) at the time of the impact.

The hard wired inputs and outputs for the ORC may be diagnosed using conventional diagnostic tools and
procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not
prove conclusive in the diagnosis of the ORC or the electronic controls or communication between other
modules and devices that provide features of the supplemental restraint system. The most reliable, efficient, and
accurate means to diagnose the ORC or the electronic controls and communication related to ORC operation
requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

REMOVAL

OCCUPANT RESTRAINT CONTROLLER

WARNING:

To avoid serious or fatal injury on vehicles equipped with side curtain
airbags, disable the Supplemental Restraint System (SRS) before
attempting any Occupant Restraint Controller (ORC) diagnosis or service.
The ORC contains a rollover sensor, which enables the system to deploy

2007 Dodge Nitro R/T

2007 RESTRAINTS Service Information - Nitro

the side airbags in the event of a vehicle rollover event. If an ORC is
accidentally rolled during service while still connected to battery power,
the side curtain airbags will deploy. Disconnect 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 SRS. Failure to take the proper precautions
could result in accidental airbag deployment.

WARNING:

To avoid serious or fatal injury on vehicles equipped with airbags, disable
the Supplemental Restraint System (SRS) before attempting any steering
wheel, steering column, airbag, Occupant Classification System (OCS),
seat belt tensioner, impact sensor, or instrument panel component
diagnosis or service. Disconnect 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 SRS. Failure to take the proper precautions could result in
accidental airbag deployment.

WARNING:

To avoid serious or fatal injury, never strike or drop the Occupant
Restraint Controller (ORC), as it can damage the impact sensor or affect
its calibration. The ORC contains the impact sensor, which enables the
system to deploy the SRS components. If an ORC is accidentally dropped
during service, the module must be scrapped and replaced with a new
unit. Failure to observe this warning could result in accidental,
incomplete, or improper SRS component deployment.

CAUTION: On vehicles equipped with the Occupant Classification System (OCS),

never replace both the Occupant Restraint Controller (ORC) and the
Occupant Classification Module (OCM) at the same time. If both require
replacement, replace one. Then perform the Supplemental Restraint
System (SRS) verification test before replacing the other. Both the ORC
and the OCM store 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.

NOTE:

The Occupant Restraint Controller (ORC) should only be removed as a
complete unit with the molded plastic mounting bracket. The service
replacement ORC is supplied already installed on a new bracket.

2007 Dodge Nitro R/T

2007 RESTRAINTS Service Information - Nitro