Air Bag Systems: Description and Operation
AIRBAG SYSTEMA dual front airbag system is a standard equipment safety feature on this model. The system includes an inflatable airbag module in the center of the steering wheel, and a second inflatable airbag module in the instrument panel where the glove box would normally be located. This system is designed to reduce serious injuries to the driver and front seat passenger during a frontal impact of the vehicle.
To test this passive restraint system, refer to the proper Body Diagnostic Procedures. If an airbag module assembly is defective and non-deployed, refer to the Chrysler Corporation current parts return list in the Warranty Policies and Procedures for the proper handling procedures.
Following are general descriptions of the major components in the airbag system.
WARNING:
- THE AIRBAG SYSTEM IS A SENSITIVE, COMPLEX ELECTROMECHANICAL UNIT. BEFORE ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIR-BAG SYSTEM OR RELATED STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENTS YOU MUST FIRST DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE. THEN WAIT TWO MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO DO THIS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
- THE AIRBAG MODULE INFLATOR ASSEMBLY CONTAINS SODIUM AZIDE 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. DO NOT ATTEMPT TO DISMANTLE THE MODULE OR TAMPER WITH ITS INFLATOR. DO NOT PUNCTURE, INCINERATE, OR BRING INTO CONTACT WITH ELECTRICITY. DO NOT STORE AT TEMPERATURES EXCEEDING 93°C (200°F).
- REPLACE AIRBAG SYSTEM COMPONENTS ONLY WITH PARTS SPECIFIED IN THE CHRYSLER MOPAR PARTS CATALOG. SUBSTITUTE PARTS MAY APPEAR INTERCHANGEABLE, BUT INTERNAL DIFFERENCES MAY RESULT IN INFERIOR OCCUPANT PROTECTION. THE FASTENERS, SCREWS, AND BOLTS ORIGINALLY USED FOR THE AIRBAG SYSTEM COMPONENTS HAVE SPECIAL COATINGS AND ARE SPECIFICALLY DESIGNED FOR THE AIR-BAG SYSTEM. THEY MUST NEVER BE REPLACED WITH SUBSTITUTES. ANY TIME A NEW FASTENER IS NEEDED, REPLACE IT WITH THE CORRECT FASTENERS PROVIDED IN THE SERVICE PACKAGE OR SPECIFIED IN THE CHRYSLER MOPAR PARTS CATALOG.
- WHEN A STEERING COLUMN HAS AN AIRBAG MODULE ATTACHED, NEVER PLACE THE COLUMN ON THE FLOOR OR ANY OTHER SURFACE WITH THE STEERING WHEEL OR AIRBAG MODULE FACE DOWN.
AIRBAG CONTROL MODULE (ACM)
The driver and passenger airbag system is a safety device designed to reduce the risk of fatality or serious injury, caused by a frontal impact of the vehicle.
The Airbag Control Module (ACM) contains the impact sensor and energy reserve capacitor. The ACM monitors the system to determine the system readiness, The ACM contains on-board diagnostics and will light the AIRBAG warning lamp in the message center when a problem occurs.
The impact sensor provides verification of the direction and severity of the impact. One impact sensor is used. It is located inside the Airbag Control Module (ACM) which is mounted on a bracket, behind the instrument panel center bezel, underneath the radio. The impact sensor is an accelerometer that senses deceleration. The deceleration pulses are sent to a microprocessor which contains a decision algorithm. When an impact is severe enough to require airbag protection, the ACM microprocessor sends a signal that completes the electrical circuit to the driver and passenger airbags. The sensor is calibrated for the specific vehicle and reacts to the severity and direction of the impact.
CLOCKSPRING
The clockspring is mounted on the steering column behind the steering wheel. This assembly consists of a flat, ribbon like, electrically conductive tape that winds and unwinds with the steering wheel rotation.
It is used to maintain a continuous electrical circuit between the wiring harness and the Driver Airbag Module.
The clockspring must be properly centered when it is installed on the steering column following any service removal, or it will be damaged. See the Clockspring Centering procedure for more information.
The clockspring cannot be repaired. If the clockspring is faulty, damaged, or if the airbag has been deployed, the clockspring must be replaced.
DRIVER AIRBAG MODULE
The Driver Airbag Module protective trim cover is the most visible part of the Driver Airbag System. The module is mounted directly to the steering wheel. Located under the Driver Airbag Module trim cover are the horn switch, the airbag cushion, and the airbag cushion supporting components. The Driver Airbag Module includes a housing to which the cushion and inflator are attached and sealed. The Driver 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 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 Driver Airbag Module and forms a decorative cover in the center of the steering wheel. Upon airbag deployment, the trim cover will split at the predetermined breakout line around the perimeter of the horn switch.
STORAGE
An airbag module must be stored in its original, special container until used for service. Also, it must be stored in a clean, dry environment, away from sources of extreme heat, sparks, and high electrical energy Always place or store an airbag module on a surface with its trim cover or airbag side facing up, to minimize movement in case of an accidental deployment.
IMPACT SENSOR
The impact sensor provides verification of the direction and severity of an impact. One impact sensor is used. It is located inside the airbag control module (ACM), which is mounted to the floor transmission tunnel, under the instrument panel and forward of the floor console.
The impact sensor is an accelerometer that senses the rate of deceleration. The microprocessor in the ACM monitors the impact sensor signal. A pre-programmed decision algorithm in the microprocessor determines when the deceleration rate indicates an impact that is severe enough to require airbag system protection. The ACM then sends an electrical signal to deploy the airbag system components. The sensor is calibrated for the specific vehicle.
The impact sensor is only serviced as a unit with the ACM. The sensor cannot be repaired or adjusted and, if faulty or damaged, the ACM unit must be replaced.
PASSENGER AIRBAG MODULE
The Passenger Airbag Module door is the most visible part of the passenger airbag system. The Passenger Airbag Module contains a housing to which the cushion and inflator are attached and sealed. The Passenger 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 Passenger 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 airbag door has predetermined breakout lines concealed beneath its decorative cover. Upon airbag deployment, the air bag door will split at the breakout lines and the door will pivot out of the way. Following an airbag deployment, the airbag door and Passenger Airbag Module must be replaced.
The passenger side airbag can be disabled using the Passenger Airbag ON/OFF Switch.
STORAGE
An airbag module must be stored in its original, special container until used for service. Also, it must be stored in a clean, dry environment, away from sources of extreme heat, sparks, and high electrical energy Always place or store an airbag module on a surface with its trim cover or airbag side facing up, to minimize movement in case of an accidental deployment.
PASSENGER AIRBAG ON/OFF SWITCH
A Passenger Airbag ON/OFF Switch located on the instrument panel allows the passenger side airbag module to be disabled when certain child restraint devices are being used in the right seating position. The passenger airbag ON/OFF switch is equipped with a key cylinder so that the switch position can only be changed using an ignition key. When the ignition switch is in the ON position and the passenger side airbag is disabled, a Light-Emitting Diode (LED) illuminates an "OFF" indicator lamp on the face plate of the switch.
To actuate the passenger airbag ON/OFF switch, insert the ignition key in the switch key cylinder. The switch key cylinder is then rotated with the ignition key to its clockwise stop (the key cylinder slot will be aligned with the OFF indicator lamp) to disable the passenger side airbag. When the passenger airbag ON/OFF switch key cylinder is rotated with the ignition key to its counterclockwise stop (the key cylinder slot will be in a vertical position), the OFF indicator lamp will be extinguished and the passenger side airbag module will once again be enabled.
WARNING: THE KEY MUST ALWAYS BE REMOVED FROM THE PASSENGER AIRBAG ON/OFF SWITCH KEY CYLINDER AFTER THE SWITCH HAS BEEN USED. NEVER LEAVE A KEY IN THE PASSENGER AIRBAG ON/OFF SWITCH KEY CYLINDER.
The passenger airbag ON/OFF switch cannot be adjusted or repaired and, if faulty or damaged, the switch assembly MUST be replaced.
WARNING: IN THE EVENT OF AN AIRBAG DEPLOYMENT, THE PASSENGER AIRBAG ON/OFF SWITCH "MUST" BE REPLACED.