Airbag System Description

Airbag System
The Airbag Control Module (ACM) is secured to a bracket on the floor panel transmission tunnel below the instrument panel inside the vehicle. The ACM mounting bracket also serves as the instrument panel center support. The ACM contains a microprocessor, the impact sensor, and energy storage capacitor. The microprocessor contains the airbag system logic. The ACM system logic includes On-Board Diagnostics (OBD) capability, and communicates with the instrument cluster circuitry on the Chrysler Collision Detection (CCD) data bus to control the airbag indicator lamp.

The microprocessor in the ACM monitors the impact sensor signal and the airbag system electrical circuits to determine the system readiness. If the ACM detects a monitored system fault, it sends messages to the instrument cluster on the CCD data bus to turn on the airbag indicator lamp. A pre-programmed decision algorithm in the ACM microprocessor determines when the deceleration rate signaled by the impact sensor indicates an impact that is severe enough to require airbag system protection. When the programmed conditions are met, the ACM sends an electrical signal to deploy the airbag system components.

Only one impact sensor is used in this airbag system. The impact sensor is an accelerometer that senses the rate of vehicle deceleration, which provides verification of the direction and severity of an impact. The impact sensor is calibrated for the specific vehicle, and is only serviced as a unit with the ACM.

The ACM also contains an energy-storage capacitor. This capacitor stores enough electrical energy to deploy the airbags, for one second following a battery disconnect or failure during an impact. The purpose of the capacitor is to provide airbag system protection in a severe secondary impact if the initial impact has damaged or disconnected the battery, but was not severe enough to deploy the airbags.

Warning: The airbag system is a sensitive, complex electromechanical unit. Before attempting to diagnose or service any airbag 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.

Note:Never strike or kick the airbag control module, as it can damage the impact sensor or affect its calibration. If an airbag control module is accidentally dropped during service, the module must be scrapped and replaced with a new unit.

Air Bag Warning Lamp
The airbag warning lamp is the only point at which the customer can observe "symptoms" of a system malfunction. Whenever the ignition key is turned to the "run" or "start" position, the MIC performs a lamp check by turning the AIRBAG warning lamp on for 6-8 seconds. If the lamp remains off, it means that the ACM has checked the system and found it to be free of discernible malfunctions. If the lamp remains on, there could be an active fault in the system or the MIC lamp circuit may be internally shorted to ground. If the lamp comes on and stays on for a period longer than 6-8 seconds then goes off, there is usually an intermittent problem in the system.

The MIC monitors the airbag warning lamp and seat belt warning lamp during the bulb check for a defective bulb or lamp driver circuit, The MIC tests the airbag lamp during the cluster bulb check and substitutes the seat belt lamp if the airbag lamp is defective. If the airbag lamp is defective the MIC will turn the seat belt light on and off approximately 30 times to warn the driver that the airbag lamp is defective. The lamp status is sent to the ACM continuously via a CCD bus message. The seat belt lamp acts as a backup in the event that the AIRBAG lamp is defective. This information is sent to the ACM continuously via a CCD bus message.

Perform the WARNING LAMP BULB OR DRIVER procedure to find the cause of any customer complaint regarding the AIRBAG warning lamp, such as:

^ warning lamp does not illuminate
^ warning lamp stays illuminated with no active DTC's

Club cab and quad cab models of this vehicle are equipped with a structural seat belt system. The structural seat belt system includes a Seatbelt Control Timer Module (SCTM). The SCTM has a hardwired input to the ACM. If a fault input from the SCTM is detected, or the SCTM is not connected, the ACM sends a message to the instrument cluster on the CCD data bus to turn on the seat belt reminder lamp. See Seat Belt Control Timer Module.

The ACM cannot be repaired or adjusted and, if damaged or faulty, it must be replaced

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 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. In addition, the passenger airbag module contains argon gas pressurized to 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 (2000 f).

Clockspring
The clockspring is mounted on the steering column behind the steering wheel. This assembly consists of a plastic housing which contains a flat, ribbon-like, electrically conductive tape that winds and unwinds with the steering wheel rotation. The clockspring is used to maintain a continuous electrical circuit between the instrument panel wire harness and the driver side airbag module, the horn switch, and the vehicle speed control switches on vehicles that are so equipped. The clockspring must be properly centered when it is installed on the steering column following any service removal, or it will be damaged. The clockspring cannot be repaired it must be replaced.

Passenger Airbag Module (PAB)
The airbag door in the instrument panel top cover above the glove box is the most visible part of the passenger side airbag system. Located under the airbag door is the airbag cushion and it's 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 includes a small canister of highly compressed argon gas. The inflator seals the hole in the airbag cushion so it can discharge the compressed gas it contains directly into the cushion when supplied with the proper electrical signal. The airbag door has a living hinge at the top, which is secured to the instrument panel top cover. The door also has predetermined breakout lines concealed beneath its decorative cover. Upon airbag deployment, the airbag door will split at the breakout lines and the door will pivot out of the way.

The airbag module is secured at the bottom to the steel structural base of the instrument panel above the glove box opening. The airbag door is serviced as a unit with the passenger side airbag module, and includes the two passenger heating and air conditioning panel outlet housings. Following an airbag deployment, the airbag module and the instrument panel assembly must be replaced.

Passenger Airbag Disarm Switch
A Passenger Airbag Disarm Switch (PADS) located on the instrument panel allows the passenger airbag module to be disarmed when certain child restraint devices are being used in the right front seating position. The PADS 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 disarmed, a Light-Emitting Diode (LED) illuminates an "Off "indicator lamp on the faceplate of the switch.

To actuate the PADS switch, insert the ignition key in the switch key cylinder. The PADS 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 disarm the passenger side airbag. When the PADS 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 armed.

Note: The key must always be removed from the passenger airbag disarm switch key cylinder after the switch has been used. Never leave a key in the pads key cylinder.

The PADS cannot be adjusted or repaired and, if faulty or damaged, the PAD switch must be replaced.

Warning: 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. In addition, the passenger airbag module contains argon gas pressurized to 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 (2000 f).

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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 airbag system. They must never be replaced with any 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.

Passenger Airbag Disable Switch (PADS)
The passenger side airbag disable switch is located on the instrument panel. To de-activate the passenger side airbag, turn the key actuator switch from the horizontal position to a slanted position (pointing to the "OFF" light indicator), approximately 45 degrees clockwise from the PADS "on" position. Rotating the key actuator switch 45 degrees clockwise, remove the key completely from the switch and verify that the switch actuator hole stays in the new position (45 degrees clockwise from horizontal). The switch is spring loaded to the "on" position. It will return to the "on" position unless you remove the key. When the IGNITION is ON, this procedure will illuminate the OFF@ light indicator on the passenger airbag disable switch.

To re-enable the passenger side airbag, reverse the procedure above so that the key switch actuator is returned to a horizontal position.

NOTE: Do not turn ignition on with key in switch.
Do not turn switch with ignition on.
Do not leave key in switch.
Do not leave the key in the key actuator under any condition.