• 2015

Air Bag Replacement

2007 Chrysler Town & Country or Dodge Caravan
Air bags might be the most important safety device ever invented. Thousands of lives may have been saved in severe automotive collisions thanks to this technology. If the vehicle(s) involved in the accident is not totaled, much work needs to be done to return it to service. Among the tasks is replacement of the air bag(s).

Air Bag Safety
Before reviewing the air bag replacement procedures, several safety warnings need to be reviewed to prevent possible serious injury.

CautionSignTo avoid serious or fatal injury on vehicles equipped with the Supplemental Restraint System (SRS), better known as air bags, never attempt to repair the electrically conductive circuits or wiring components related to the SRS. Any wire harness containing broken, cut, burned or otherwise damaged electrically conductive SRS wiring, terminals or connector components must be removed and replaced with an entire new wire harness.

CautionSignReplace air bag system components with Mopar® replacement parts. Substitute parts might appear interchangeable, but internal differences can result in inferior occupant protection. The factory installed fasteners, screws and bolts have a special coating and are specifically designed for the air bag system. Do not use substitute fasteners.

CautionSignDo not place an intact undeployed air bag face down on a solid surface. The air bag will propel into the air if accidentally deployed. Also, the trim side (face) of the air bag should be pointing away from the body when carrying or handling an undeployed air bag, to minimize possibility of injury if accidental deployment occurs.

Air Bag Basics
Several combinations of air bags are used throughout the Chrysler brand product line. Earlier vehicles, such as a 2007 Chrysler Town & Country, are equipped with dual front air bags. This system might be supplemented with a knee blocker. Late model vehicles include these components, plus side curtain and rear seat air bags.

The driver air bag is located in the center of the steering wheel, beneath the driver air bag trim cover. The passenger air bag is located on the dashboard, beneath the top pad and above the glove box. The driver knee blocker air bag is secured to the instrument panel behind the steering column opening cover, and the passenger knee blocker air bag is integral to and concealed within the glove box door.

Several components are required to trigger the air bags when a severe collision occurs. Two front impact sensors, one on each side of the vehicle, are located on the rail tips, behind the bumper attachments. The OCS (Occupant Classification System) automatically suppresses, or enables the passenger air bag depending on whether the passenger seat is occupied. In addition, it determines the size of the passenger and whether the seat is occupied by a baby seat. The ORC (Occupant Restraint Controller), also known as the ACM (Airbag Control Module) is the electronic brain that makes the air bags work.

The air bags will be deployed depending on the angle and severity of the impact, not the speed of the vehicle. Deployment is based upon the rate of deceleration measured by the forces of gravity (G-force) upon the impact sensors. If the G-forces are sufficient, the ORC signals the inflator of the appropriate air bag to deploy the air bag cushion and inflate the air bag(s).

Replacing Air Bags
After an accident in which one or more air bags are deployed, replacing the air bags, in a similar manner to repairing the body damage to the vehicle, can be a time-consuming process. There is a lot more involved than just fitting a new air bag into the steering wheel and/or passenger dashboard. And the 2007 Town & Country presents a challenge that is unique to this vehicle.

As is the case with all minivans, the passenger air bag cover is part of the dashboard. When the air bag is deployed, that section of the dashboard must be replaced. It is important to note that is only true for minivans built between 2008 and 2010. Minivans built before model year 2008, like the 2007 Town & Country, and after 2010 require that the entire dashboard be replaced when servicing the air bag. That’s a big time commitment (approximately 4 hours flat rate).

Let’s review the basic tasks that must be performed when servicing deployed air bags. Let’s start with the driver air bag.

AIR BAG LOCATION COMPONENT REPLACED
Driver Driver air bag, clockspring assembly steering wheel, complete steering column assembly
Passenger Passenger air bag, instrument panel, pad assembly (dashboard)
Knee Blocker Knee blocker air bag, instrument panel, pas assembly
Curtain Curtain air bag assembly, headliner, A-, B- and C-pillar trim on the deployed side of the vehicle

 

In addition to the specifics listed, the OCS system components need to be inspected and replaced if found to be damaged. These include the (1) seat belt tensioner, (2) Occupant Classification Module (OCM), also known as the ACM, (3) passenger air bag ON/OFF indicator and (4) seat weight bladder and sensor.

Warning: Never replace both the ORC and OCM at the same time; if both require replacement, replace one and perform the Airbag System Test before replacing the other; also, the OCS must be re-zeroed, regardless if it is replaced, to ensure that the system is within proper parameters to sense occupant weight correctly.

The clean-up procedure is very important when servicing deployed air bags. Wear safety glasses, rubber gloves and long sleeved clothing when cleaning powder residue from the vehicle. Sodium hydroxide powder emitted from a deployed air bagFigure1 can cause skin, nasal and throat irritation.

Use a vacuum cleaner to remove any of this residual powder. Work from the outside in to avoid kneeling or sitting in a contaminated area. Be sure to include vacuuming the heater and A/C outlets (Figure 1). If the heater or air conditioner were in RECIRC mode at the time of the airbag deployment, operate the blower motor on low speed and vacuum the powder residue from the heater and A/C outlets. Removing all traces of the powder is necessary for passenger safety; therefore, multiple vacuum cleanings might be required to clean the interior of the vehicle.

Also, when removing an air bag, deployed or undeployed, disconnect the negative battery cable, then wait two minutes before beginning any air bag service. This time period is necessary for the air bag system reserveFigure2 capacitor to discharge. The driver air bag is removed from the steering wheel by removing two screws and disconnecting two connectors (Figure 2). After the new air bag has been installed, do not connect the negative battery cable until the system test has been performed. See operator’s manual or www.techauthority.com for more inclusive removal information.

All step-by-step procedures for removing and installing the air bag components are straightforward but time intensive.