OCCUPANT RESTRAINT CONTROLLER Dodge Durango II facelift

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 ElectroMechanical 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.

The ORC receives battery current through two circuits; 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 and take out of the instrument panel wire harness. This take out has a single eyelet terminal connector that is secured by a ground screw near the center of the instrument panel structural support. 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 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 vertical members of the radiator support 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 six additional remote impact sensors located on the left and right front door beams, the inner C-pillars and inner D-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.

The hard wired inputs and outputs for the ORC may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate SYSTEM WIRING DIAGRAMS article. 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 SRS. 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.

Scheme 38

1. Disconnect and isolate the battery negative cable. Wait two minutes for the system capacitor to discharge before further service.
2. Remove the center console from the top of the floor panel transmission tunnel. Refer to «REMOVAL»(ref-285328-S17429768402008052100000) .
3. Disconnect the two body wire harness connectors (1) from the Occupant Restraint Controller (ORC) (2) connector receptacles located on the forward facing side of the module. To disconnect the wire harness connectors from the ORC, depress the release tab and lift the lever arm on each connector.
4. Remove the three screws (3) that secure the ORC to the ORC bracket (4) that is welded onto the top of the floor panel transmission tunnel.
5. Remove the ORC from the floor panel transmission tunnel.

1. Carefully position the Occupant Restraint Controller (ORC) (2) to the ORC bracket (4) on the floor panel transmission tunnel. When the ORC is correctly positioned, the arrow on the ORC label will be pointed forward in the vehicle and the locating pin on the bottom of the right ORC mounting flange will be engaged into the locating hole in the ORC bracket.
2. Install and tighten the three screws (3) that secure the ORC to the ORC bracket that is welded onto the floor panel transmission tunnel. Tighten the screws to 11 N.m (8 ft. lbs.). CAUTION: The lever arms of the wire harness connectors for the ORC MUST be in the unlatched position before they are inserted into their connector receptacles on the ORC or they may become damaged.
3. Reconnect the two body wire harness connectors (1) to the ORC connector receptacles located on the forward facing side of the module. Be certain that the latches on both connectors are each fully engaged.
4. Reinstall the center console onto the top of the floor panel transmission tunnel. Refer to «INSTALLATION»(ref-285328-S25736462492008052100000) .
5. 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 «STANDARD PROCEDURE»(ref-285335-S06143362072008052100000) .

Scheme 39

The horizontal surface of the injection molded, thermoplastic passenger airbag door (1) is the most visible part of the passenger airbag. The passenger airbag door is located above the glove box opening on the top of the instrument panel (2) in front of the front seat passenger seating position.

Scheme 40

The outboard edges of the airbag door are secured with integral snap features (3) to the instrument panel base trim. Located below the passenger airbag door (2) within the instrument panel is the passenger airbag unit. The passenger airbag housing fits into a molded receptacle on the back of the airbag door, where twelve stamped hook formations on the forward and rearward edges of the airbag housing are engaged in mating small window openings on the forward and rearward flanges of the receptacle to secure the airbag door to the airbag housing. These airbag door fasteners and mounting provisions are all concealed beneath the instrument panel base trim. The passenger airbag unit is secured by two screws through a stamped mounting bracket (5) to the instrument panel structural support.

The passenger airbag unit used in this vehicle is a multistage, Next Generation-type that complies with revised federal airbag standards to deploy with less force than those used in some prior vehicles. The passenger airbag unit consists of a stamped and welded metal housing, the airbag cushion, the airbag inflator, and a stamped metal airbag cushion retainer plate that is secured to the airbag housing with four studs and nuts. The airbag housing contains the airbag inflator and the folded airbag cushion. An approximately 80 centimeter (31.5 inch) wide by 90 centimeter (35.5 inch) high rectangular fabric cushion is used.

The airbag inflator (4) is a non-azide, pyrotechnic-type unit that is secured to and sealed within the airbag housing. A short four-wire pigtail harness with a keyed, yellow connector insulator (1) connects the two inflator initiators to the vehicle electrical system through a dedicated take out and connector of the instrument panel wire harness.

The passenger airbag includes the airbag door. This unit cannot be repaired, and must be replaced if deployed, ineffective, or in any way damaged.