FORD/Lincoln/Mercury 1990-2002 DESCRIPTION & OPERATION Airbag (with inflatable device and pretenssioners) System The Supplemental Airbag (with inflatable device and pretenssioners) System (SRS) including the explosive pyrotechnic device is composed of the driver's and passenger's Airbag (with inflatable device and pretenssioners) modules, clockspring, impact sensors, control module and warning lamp. The system is controlled by the diagnostic monitor on 1986-97 models, Electronic Crash Sensor (ECS) on 1998 models and Restraints Control Module (RCM) on 1999-2002 models. On most models the back-up power supply is incorporated into the control model. Some 1986-92 models may have a remote back-up power supply. Focus, LS, 1999-2002 Continental, Cougar, Town Car, 200002 Sable and Taurus models may also equipped with side impact Airbag (with inflatable device and pretenssioners) modules. Belt & Buckle PretensionerOn a few models, the belt and buckle assembly pretensioners uses the same crash sensor system as the Airbag (with inflatable device and pretenssioners) system. When the belt and buckle assembly pretensioner deploys, the buckle will move downward pulling excess webbing from the lap and shoulder safety belts. The pretensioner is a pyrotechnic device. Airbag (with inflatable device and pretenssioners) System The Supplemental Airbag (with inflatable device and pretenssioners) System (SRS) including the explosive pyrotechnic device is composed of the driver, passenger Airbag (with inflatable device and pretenssioners) module, sliding contact, impact sensors, Airbag (with inflatable device and pretenssioners) control module and warning lamp. The driver and passenger Airbag (with inflatable device and pretenssioners) modules on the 2004-06 vehicle line contain dual-stage (advanced restraint system) deployment modules. These modules deploy at one of two different rates depending upon impact severity. On late model systems 2003-2011 A few models are also equipped with optional side Airbag (with inflatable device and pretenssioners)s modules and roof panel modules. The side Airbag (with inflatable device and pretenssioners) modules mount on the outer side edges of the front seat backs and will deploy if a side collision of enough force is detected by the corresponding side impact sensor. The roof panel air bag modules deploy from the headline protecting the first and second row outboard occupants on the Five Hundred and Montego models or the fist, second and third row outboard occupants on the Freestyle model. If the headliner has the word Airbag (with inflatable device and pretenssioners) embossed on it near each B-pillar the vehicle isequipped with roof panel Airbag (with inflatable device and pretenssioners) modules. Driver Airbag (with inflatable device and pretenssioners) Module The driver Airbag (with inflatable device and pretenssioners) module is mounted in the center of the steering wheel. The module is composed of an igniter assembly, inflator, mounting plate, retainer ring, bag and liner assembly and steering wheel trim cover, . This unit may not be disassembled or serviced. Passenger Airbag (with inflatable device and pretenssioners) Module The passenger Airbag (with inflatable device and pretenssioners) module is mounted in the right-hand side of the instrument panel, . The module is composed of an igniter assembly, inflator, and reaction housing. This unit may not be disassembled or serviced. Igniter & Inflator Assembly The igniter/inflator is an integral part of the inflator assembly and is not a serviceable item. When the Airbag (with inflatable device and pretenssioners) monitor assembly signals the igniter, the igniter assembly converts the electrical signal to thermal energy, causing the ignition of the inflator gas generator. This ignition reaction will ignite the sodium oxide/ copper oxide or potassium generator in the inflator, to produce nitrogen gas, causing the Airbag (with inflatable device and pretenssioners) to inflate. Airbag (with inflatable device and pretenssioners) Assembly The Airbag (with inflatable device and pretenssioners) is constructed of neoprene coated nylon. The Airbag (with inflatable device and pretenssioners) fills to full volume in approximately 40 milliseconds. The Airbag (with inflatable device and pretenssioners) is not a serviceable item. Driver Airbag (with inflatable device and pretenssioners) Mounting Plate & Retainer Ring The mounting plate and retainer ring attaches and seals the bag assembly to the inflator. The mounting bracket is also used to attach the trim cover and to mount the entire module to the steering wheel. These items are components of the Airbag (with inflatable device and pretenssioners) module and cannot be serviced. Driver Airbag (with inflatable device and pretenssioners) Liner & Steering Wheel Trim Cover The liner is an injection molded plastic component which encases the Airbag (with inflatable device and pretenssioners) assembly and provides support for the steering wheel trim cover assembly. When the Airbag (with inflatable device and pretenssioners) is activated, fail seams molded into the liner and steering wheel trim cover separate to allow inflation of the Airbag (with inflatable device and pretenssioners) assembly. The liner is a component of the Airbag (with inflatable device and pretenssioners) module and is not a serviceable item. Passenger Airbag (with inflatable device and pretenssioners) Reaction Housing The reaction housing provides support and a reaction surface for the inflator. It is also used to attach the trim cover. the reaction housing also provides a means for mounting the Airbag (with inflatable device and pretenssioners) module to the instrument panel. Passenger Airbag (with inflatable device and pretenssioners) Trim Cover The trim cover is attached to the reaction housing. It is colored to match the instrument panel. The trim cover retains the Airbag (with inflatable device and pretenssioners) in the reaction housing. Some trim covers incorporate a mounded tear seam which separates when the Airbag (with inflatable device and pretenssioners) inflates. Other trim covers incorporate a corrugated hinge which allows the trim cover up and out of the way when the Airbag (with inflatable device and pretenssioners) inflates. Electrical System The Airbag (with inflatable device and pretenssioners) is powered directly from the battery or 12 volt power supply circuit (hybrids) and back-up power supply. The system can function with the ignition switch in any position, including off and lock. The system can also function when no one is sitting in the driver seat. The electrical system performs three main functions; it detects an impact, switches electric power to the igniter assembly and monitors the system to determine readiness. The electrical system components include an electronic monitor assembly, Airbag (with inflatable device and pretenssioners) system readiness indicator lamp, wiring harness, sensors and an igniter assembly. Airbag (with inflatable device and pretenssioners) Diagnostic Monitor The Airbag (with inflatable device and pretenssioners) diagnostic monitor assembly contains a microcomputer that monitors the electrical system components and connections. The assembly performs a self inspection of the microcomputer internal circuits and energizes the system indicator lamp during prove out and whenever a fault occurs. System defects can be detected and translated into a coded lamp display. If certain faults occur, the system will be disarmed by a firing disarm device built into the diagnostic monitor assembly. Airbag (with inflatable device and pretenssioners) Indicator Lamp The Airbag (with inflatable device and pretenssioners) indicator lamp is an instrument cluster mounted lamp that will momentarily light whenever the ignition switch is turned from Off to Run if the Airbag (with inflatable device and pretenssioners) system is working properly. If the system is not functioning properly, the lamp will fail to light, stay on continuously or light in a flashing mode, if a system defect exists and the lamp is faulting, an audible tone will be heard. If a fault occurs after the system prove out, the lamp will light either continuously or in a coded flashing mode. Tone Generator On a few models a series of five sets of five tones will be heard if the readiness lamp is out and a fault occurs in the system. The tone pattern will repeat periodically until the fault and lamp outage are serviced. Crash Sensors The sensor assembly is an electrical switch which reacts to impacts according to direction and force. It discriminates between impacts that require Airbag (with inflatable device and pretenssioners) inflation and impacts that do not require Airbag (with inflatable device and pretenssioners) inflation. When an impact occurs that requires Airbag (with inflatable device and pretenssioners) inflation, the sensor contacts close, completing the electrical circuit required for system operation. At least two sensors must be activated to inflate the Airbag (with inflatable device and pretenssioners). Knee Diverter The knee diverter is located under the steering column behind the steering column opening trim panel, Fig. 3. It is designed to divert some of the impact when contacted by the driver knees, and to protect the knees during impact. Deployable Steering Column The deployable steering column includes a deployable device that, once deployed, reduces the amount of force required to collapse the steering column during a collision. This deployable device is activated by the Restraints Control Module (RCM) depending on when the module detects a crash event force exceeding a programmed limit and the position of the driver seat. After a deployment event the steering column and overlay wiring harness must be replaced. Seat Belt Pretensioner System As part of supplemental restraint system, the seat belt retractors are equipped with pretensioners. These pretensioners rotate the retractors to remove excess slack from the belt webbing. The pretensioners are activated by the Restraints Control Module (RCM) when the module detects a crash force in excess of a programmed limit. Seat Belt Switches The seat belt buckles on models with pretensioners are equipped with switches. The switches indicate to the restraints control module (RCM) whether the belts are connected or disconnected. The RCM uses this information in determining the Airbag (with inflatable device and pretenssioners) module deployment rates. Seat Track Position Sensor The seat track position sensor informs the Restraints Control Module (RCM) of the driver seat position. The RCM uses this information in calculating the deployment rate of the Airbag (with inflatable device and pretenssioners) modules. Occupant Classification Sensor This sensor informs the Occupant Classification Sensor (OCS) control module of the weight of any occupant or object in the passenger seat. Based on predetermined limits, the occupant classification sensor control module will inform the Restraints Control Module (RCM) if passenger Airbag (with inflatable device and pretenssioners) module is to be deactivated. The RCM uses this information to determine if passenger Airbag (with inflatable device and pretenssioners) module requires deployment during a deployable crash.