Part 2 of 2
DRIVER AIRBAGThe driver airbag protective trim cover is the most visible part of the driver airbag. The airbag used in this model is a Next Generation-type that complies with revised federal airbag standards to deploy with less force than those used in some prior models. The driver airbag is located in the center of the steering wheel, where it is secured with two screws to the steering wheel armature. Concealed beneath the driver airbag trim cover are the horn switch, the folded airbag cushion, the airbag retainer or housing, the airbag inflator, and the retainers that secure the trim cover to the airbag housing. The resistive membrane-type horn switch is secured with heat stakes to the inside surface of the airbag trim cover, between the trim cover and the folded airbag cushion. The airbag inflator is a conventional pyrotechnic-type unit that is secured with nuts to four studs on the back of the stamped metal airbag housing.
The driver airbag trim cover has locking blocks molded into the back side of it that engage a lip formed around the perimeter of the airbag housing. Two stamped metal retainers then fit over the inflator mounting studs on the back of the airbag housing and tabs on the retainer are engaged in slots on the inside of the trim cover, securely locking the cover into place. One horn switch pigtail wire has an eyelet terminal connector that is captured on the upper left inflator mounting stud between the inflator and the upper trim cover retainer. The connector insulator of the other horn switch pigtail wire is routed between the upper right inflator mounting stud and the inflator, where it is captured by a small plastic that is pushed onto the stud. The driver airbag cannot be repaired, and must be replaced if deployed or in any way damaged. The driver airbag trim cover and horn switch are available as a unit, and may be disassembled from the driver airbag for service replacement.
The driver airbag is deployed by an electrical signal generated by the Airbag Control Module (ACM) through the driver airbag line 1 and line 2 (or squib) circuits. When the ACM sends the proper electrical signal to the airbag inflator, the electrical energy generates enough heat to initiate a small pyrotechnic charge which, in turn, ignites chemical pellets within the inflator. Once ignited, these chemical pellets burn rapidly and produce a large quantity of nitrogen gas. The inflator is sealed to the back of the airbag housing and a diffuser in the inflator directs all of the nitrogen gas into the airbag cushion, causing the cushion to inflate. As the cushion inflates, the driver airbag trim cover will split at predetermined break-out lines, then fold back out of the way along with the horn switch. Following an airbag deployment, the airbag cushion quickly deflates by venting the nitrogen gas towards the instrument panel through the porous fabric material used on the steering wheel side of the airbag cushion.
Some of the chemicals used to create the nitrogen gas are considered hazardous in their solid state, before they are burned, but they are securely sealed within the airbag inflator. However, the nitrogen gas that is produced when the chemicals are burned is harmless. A small amount of residue from the burned chemicals may cause some temporary discomfort if it contacts the skin, eyes, or breathing passages. If skin or eye irritation is noticed, rinse the affected area with plenty of cool, clean water. If breathing passages are irritated, move to another area where there is plenty of clean, fresh air to breath. If the irritation is not alleviated by these actions, contact a physician.
PASSENGER AIRBAG
The rearward facing surface of the passenger airbag door above the glove box is the most visible part of the passenger airbag. The airbag used in this model is a Next Generation-type that complies with revised federal airbag standards to deploy with less force than those used in some prior models. The passenger airbag is located in the instrument panel in front of the front seat passenger seating position, where it is secured to the instrument panel. Concealed beneath the passenger airbag door are the folded airbag cushion, the airbag retainer or housing, and the airbag inflator. The airbag inflator is a hybrid-type unit that is secured to and sealed within the stamped steel airbag housing along with the folded airbag cushion. The airbag housing stamping also includes the two mounting brackets, one front and one rear. The front bracket is secured beneath the instrument panel top cover with screws to the instrument panel structural support. The rear bracket is secured with screws to the upper glove box opening reinforcement. A yellow connector on the end of a short, two-wire pigtail harness connects the passenger airbag inflator to the vehicle electrical system.
The molded plastic passenger airbag door has predetermined breakout lines concealed beneath its decorative cover. The lower edge of the passenger airbag door is secured to the airbag housing, and includes the two passenger side panel outlets. The sides and upper edges are secured to the instrument panel top cover with five molded tabs that are each fit with a small metal retainer. The five retainers are snapped into five slotted receptacles located around the sides and top of the airbag door opening in the instrument panel top cover. Following a passenger airbag deployment, the passenger airbag and airbag door unit must be replaced. The passenger airbag cannot be repaired, and must be replaced if faulty or in any way damaged. The passenger airbag door is serviced only as a unit with the passenger airbag, and includes the two passenger side heating and air conditioning panel outlet housings and barrels.
The passenger airbag is deployed by an electrical signal generated by the Airbag Control Module (ACM) through the passenger airbag line 1 and line 2 (or squib) circuits. The hybrid-type inflator assembly includes a small canister of highly compressed argon gas. When the ACM sends the proper electrical signal to the airbag inflator, the electrical energy generates enough heat to ignite chemical pellets within the inflator. Once ignited, these chemical pellets burn rapidly and produce the pressure necessary to rupture a containment disk in the argon gas canister. The inflator and argon gas canister are sealed to the airbag cushion so that all of the released argon gas is directed into the airbag cushion, causing the cushion to inflate. As the cushion inflates, the passenger air- bag door will split at the breakout lines and the door will pivot out of the way. Following an airbag deployment, the airbag cushion quickly deflates by venting the argon gas through the porous fabric material used on each end panel of the airbag cushion.
Some of the chemicals used to create the pressure to burst the argon gas containment disk are considered hazardous in their solid state, before they are burned, but they are securely sealed within the air- bag inflator. However, the gas that is produced when the chemicals are burned is harmless. A small amount of residue from the burned chemicals may cause some temporary discomfort if it contacts the skin, eyes, or breathing passages. If skin or eye irritation is noticed, rinse the affected area with plenty of cool, clean water. If breathing passages are irritated, move to another area where there is plenty of clean, fresh air to breath. If the irritation is not alleviated by these actions, contact a physician immediately.
PASSENGER AIRBAG ON/OFF SWITCH
The passenger airbag ON-OFF switch is standard equipment on this model when it is not equipped with a full size rear seat. This switch is a single pole, single throw switch with a single integral red Light-emitting Diode (LED), and a non-coded key cylinder type actuator. The switch is located in the upper right corner of instrument panel cluster bezel, near the center of instrument panel to make the OFF indicator visible to all front seat occupants. When the switch is in its installed position, the only components visible through the dedicated opening of the cluster bezel are the switch face plate and nomenclature, the key cylinder actuator, and a small round lens with the text "OFF" imprinted on it. The "ON" position of the switch is designated by text imprinted upon the face plate of the switch, but is not illuminated. The remainder of the switch is concealed behind the switch face plate and the instrument panel cluster bezel.
The passenger airbag ON-OFF switch housing is constructed of molded plastic and has three integral mounting tabs. These mounting tabs are used to secure the switch to the back of the molded plastic switch face plate with three small screws. The molded plastic face plate also has three integral mounting tabs that are used to secure the switch and face plate unit to the instrument panel carrier with three additional screws. Two short pigtail wires with molded plastic connector insulators exit the back of the switch housing and connect the switch to the vehicle electrical system through two dedicated take outs of the instrument panel wire harness. The harness take outs are equipped with molded plastic connector insulators that are keyed and latched to ensure proper and secure switch electrical connections. The passenger airbag ON/OFF switch cannot be adjusted or repaired and, if faulty or damaged, the switch must be replaced.
The passenger airbag ON-OFF switch allows the customer to turn the passenger airbag function ON or OFF to accommodate certain uses of the right front seating position where airbag protection may not be desired. See the owner's manual in the vehicle glove box for specific recommendations on when to enable or disable the passenger airbag. The OFF indicator of the switch will be illuminated whenever the switch is turned to the OFF position. The ignition key is the only key or object that should ever be inserted into the switch. The ON-OFF switch requires only a partial key insertion to fully depress a spring-loaded locking plunger. The spring-loaded locking plunger prevents the user from leaving the key in the switch. The key will be automatically ejected when force is not applied. To actuate the passenger side airbag ON/OFF switch, insert the ignition key into the switch key actuator far enough to fully depress the plunger and rotate to the desired switch position. When the switch key actuator is rotated to its clockwise stop (the key actuator slot will be aligned with the OFF indicator lamp), the OFF indicator is illuminated and the passenger airbag is disabled. When the switch is rotated to its counterclockwise stop (the key actuator slot will be in a vertical position), the OFF indicator will be extinguished and the passenger airbag is enabled.
The passenger airbag switch is connected in series between the Airbag Control Module (ACM) and the passenger airbag inflator unit. When the switch is in the ON position, the switch connects the ACM directly to the passenger airbag inflator. When the switch is in the OFF position it interrupts the inflator circuits, but replaces the normal resistance in these circuits with an internal resistor. Thus, the ACM is unable to distinguish the mode of the switch and still sends an electrical signal as though it were deploying the passenger airbag when it detects a sufficient impact. However, the switch position should not be changed while the ignition switch is in the ON position, as the ACM may detect a fault, record a Diagnostic Trouble Code (DTC), and illuminate the Airbag indicator in response to a momentary open it senses in the passenger airbag inflator circuits as the ON/OFF switch changes states.
SEAT BELT SWITCH
The seat belt switch is a small, normally closed, single pole, single throw, leaf contact, momentary switch. Only one seat belt switch is installed in the vehicle, and it is integral to the buckle of the driver seat belt buckle-half, located near the inboard side of the driver side front seating position. The seat belt switch is connected to the vehicle electrical system through a two-wire pigtail wire and connector on the seat belt buckle-half, which is connected to a wire harness connector and take out of the body wire harness.
The seat belt switch cannot be adjusted or repaired and, if faulty or damaged, the entire driver seat belt buckle-half unit must be replaced.
The seat belt switch is designed to control a path to ground for the seat belt switch sense input of the Electro-Mechanical Instrument Cluster (EMIC). when the driver side seat belt tip-half is inserted in the seat belt buckle, the switch opens the path to ground; and, when the driver side seat belt tip-half is removed from the seat belt buckle, the switch closes the ground path. The switch is actuated by the latch mechanism within the seat belt buckle. The EMIC monitors the driver seat belt switch status, then controls the seatbelt indicator and sends hard wired chime requests to the Central Timer Module (CTM) based upon that input.
The seat belt switch receives ground through its pigtail wire connection to the body wire harness from another take out of the body wire harness. An eyelet terminal connector on that ground take out is secured under a nut to a ground stud on the left lower B-pillar (standard cab models) or the left lower cowl side inner panel (club cab and quad cab models). The seat belt switch is connected in series between ground and the seat belt switch sense input of the EMIC.