RAM 2500 Truck 2WD L6-5.9L DSL Turbo VIN C (2002)
Air Bag: Description and Operation
Driver Airbag
DRIVER AIRBAG MODULE (DAB)
The airbag protective trim cover is the most visible part of the driver side airbag system. The module is mounted directly to the steering wheel. Located
under the trim cover are the horn switch, the airbag cushion, and the airbag cushion supporting components. The airbag module includes a housing to
which the cushion and inflator are attached and sealed. The airbag module cannot be repaired, and must be replaced if deployed or in any way damaged.
The inflator assembly is mounted to the back of the airbag module. The inflator seals the hole in the airbag cushion so it can discharge the gas it
produces directly into the cushion when supplied with the proper electrical signal. The protective trim cover is fitted to the front of the airbag module
and forms a decorative cover in the center of the steering wheel. Upon airbag deployment, this cover will split at a predetermined breakout line.
WARNING: THE AIRBAG MODULE INFLATOR ASSEMBLY CONTAINS SODIUM AND POTASSIUM NITRATE. THESE
MATERIALS ARE POISONOUS AND EXTREMELY FLAMMABLE. CONTACT WITH ACID, WATER, OR HEAVY
METALS MAY PRODUCE HARMFUL AND IRRITATING GASES (SODIUM HYDROXIDE IS FORMED IN THE
PRESENCE OF MOISTURE) OR COMBUSTIBLE COMPOUNDS. IN ADDITION, THE PASSENGER AIRBAG MODULE
CONTAINS ARGON GAS PRESSURIZED OVER 2500 PSI. DO NOT ATTEMPT TO DISMANTLE AN AIRBAG MODULE
OR TAMPER WITH ITS INFLATOR. DO NOT PUNCTURE, INCINERATE, OR BRING INTO CONTACT WITH
ELECTRICITY. DO NOT STORE AT TEMPERATURE EXCEEDING 93 ° C (200 ° F).
The 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 retainer 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 breakout 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.
