2007 Grand Cherokee WK Factory Service Manual 8 - ELECTRICAL

CURTAIN AIRBAG

DESCRIPTION



Side curtain airbags are standard equipment for this vehicle when it is also equipped with dual front airbags. These airbags are passive, inflatable, Supplemental Restraint System (SRS) components, and vehicles with this equipment can be readily identified by a molded identification trim button with the SRS - AIRBAG logo located on the headliner above each B and C-pillar. This system is designed to reduce injuries to the vehicle occupants in the event of a side impact collision or a vehicle rollover incident.



Vehicles equipped with side curtain airbags have two individually controlled curtain airbag units. These airbag units are concealed and mounted above the headliner where they are each secured to one of the roof side rails. Each folded airbag cushion is contained within a fabric wrap and extruded plastic channels that extend along the roof rail from the A-pillar at the front of the vehicle to just behind the C-pillar at the rear of the vehicle.

A long tether extends down the A-pillar from the front of the airbag cushion. The end of the tether is secured to a slot in the sheet metal with a metal hook, while two additional plastic clips secure the tether to the inside surface of the A-pillar.

The hybrid-type inflator for each airbag is secured to the roof rail at the rear of the airbag unit between the C-pillar and the D-pillar, and is connected to the airbag cushion by a long tubular manifold. The inflator bracket and the extruded airbag cushion channel are secured with both plastic push-in fasteners and screws to box nuts and U-nuts installed in the roof rail. The inflator is initially hung from the roof rail by hooks that are integral to the inflator bracket.

The airbag inflator is connected to the vehicle electrical system through a dedicated take out and connector of the body wire harness near the top of the D-pillar. The body wire harness connects the airbag unit to the Occupant Restraint Controller (ORC).

The side curtain airbag unit cannot be adjusted or repaired and must be replaced if deployed, ineffective, or in any way damaged. Once a side curtain airbag has been deployed, the complete airbag unit, the headliner, the upper A, B, and C-pillar trim, and all other visibly damaged components must be replaced.

OPERATION

Each side curtain airbag is deployed individually by an electrical signal generated by the Occupant Restraint Controller (ORC) to which it is connected through left or right curtain airbag line 1 and line 2 (or squib) circuits. The hybrid-type inflator assembly for each airbag contains a small canister of highly compressed inert gas. When the ORC sends the proper electrical signal to the airbag inflator, the electrical energy creates enough heat to ignite chemical pellets within the inflator.

Once ignited, these chemicals burn rapidly and produce the pressure necessary to rupture a containment disk in the inert gas canister. The inflator and inert gas canister are sealed and connected to a tubular manifold so that all of the released gas is directed into the folded curtain airbag cushion, causing the cushion to inflate. As the airbag cushion inflates it will drop down from the roof rail between the edge of the headliner and the side glass/body pillars to form a curtain-like cushion to protect the vehicle occupants during a side impact collision or a vehicle rollover incident.

The front tether keeps the side curtain bag taut to the side of the vehicle, thus ensuring that the bag will deploy in the proper position. Following the airbag deployment, the airbag cushion slowly deflates by venting the inert gas through the loose weave of the cushion fabric, and the deflated cushion hangs down loosely from the roof rail.

Proper diagnosis of the side curtain airbag inflator and squib circuits requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

REMOVAL

WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the supplemental restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

WARNING: To avoid personal injury or death, when removing a deployed airbag, rubber gloves, eye protection, and a long-sleeved shirt should be worn. There may be deposits on the airbag unit and other interior surfaces. In large doses, these deposits may cause irritation to the skin and eyes.

WARNING: To avoid personal injury or death, use extreme care to prevent any foreign material from entering the side curtain airbag, or becoming entrapped between the side curtain airbag cushion and the headliner. Failure to observe this warning could result in occupant injuries upon airbag deployment.

NOTE: The following procedure is for replacement of an ineffective or damaged side curtain airbag. If the airbag is ineffective or damaged, but not deployed, review the recommended procedures for handling non-deployed supplemental restraints. (Refer to 8 - ELECTRICAL/RESTRAINTS - STANDARD PROCEDURE - HANDLING NON-DEPLOYED SUPPLEMENTAL RESTRAINTS). If the side curtain airbag has been deployed, review the recommended procedures for service after a supplemental restraint deployment before removing the airbag from the vehicle. (Refer to 8 - ELECTRICAL/RESTRAINTS - STANDARD PROCEDURE - SERVICE AFTER A SUPPLEMENTAL RESTRAINT DEPLOYMENT).




1. Disconnect and isolate the battery negative cable. Wait two minutes for the system capacitor to discharge before further service.
2. Remove the headliner from the vehicle.
(Refer to 23 - BODY/INTERIOR/HEADLINER - REMOVAL).
3. Disconnect the body wire harness connector (2) for the side curtain airbag from the connector receptacle at the back of the inflator (1) on the roof side rail (3) near the D-pillar.




4. Disengage the two plastic retainers, then the hook that secure the side curtain airbag front tether to the inner A-pillar.
5. Remove the six screws that secure the side curtain airbag channel to the box nuts in the inner roof side rail.
6. Disengage the two plastic push-in fasteners that secure the channel to the roof side rail at the top of the B-pillar.
7. Disengage the two plastic push-in fasteners that secure the channel to the roof side rail at the top of the C-pillar.
8. Remove the two screws that secure the inflator mounting bracket to the U-nuts in the inner roof side rail.
9. Disengage the integral hooks on the inflator mounting bracket from the locating holes in the roof side rail.
10. Remove the side curtain airbag from the vehicle as a unit.

INSTALLATION

WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the supplemental restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

WARNING: To avoid personal injury or death, when removing a deployed airbag, rubber gloves, eye protection, and a long-sleeved shirt should be worn. There may be deposits on the airbag unit and other interior surfaces. In large doses, these deposits may cause irritation to the skin and eyes.

WARNING: To avoid personal injury or death, use extreme care to prevent any foreign material from entering the side curtain airbag, or becoming entrapped between the side curtain airbag cushion and the headliner. Failure to observe this warning could result in occupant injuries upon airbag deployment.

NOTE: The following procedure is for replacement of an ineffective or damaged side curtain airbag. If the airbag is ineffective or damaged, but not deployed, review the recommended procedures for handling non-deployed supplemental restraints. (Refer to 8 - ELECTRICAL/RESTRAINTS - STANDARD PROCEDURE - HANDLING NON-DEPLOYED SUPPLEMENTAL RESTRAINTS). If the side curtain airbag has been deployed, review the recommended procedures for service after a supplemental restraint deployment before removing the airbag from the vehicle. (Refer to 8 - ELECTRICAL/RESTRAINTS - STANDARD PROCEDURE - SERVICE AFTER A SUPPLEMENTAL RESTRAINT DEPLOYMENT).






1. Check to be certain that the two U-nuts for the side curtain airbag inflator bracket and the six box nuts for the airbag channel are properly installed in the inner roof rail and that they are in good condition.
2. Position the side curtain airbag into the vehicle as a unit.
3. Engage the integral hooks on the side curtain airbag inflator mounting bracket into the locating holes in the inner roof side rail near the D-pillar.
4. Install and tighten the two screws that secure the inflator mounting bracket to the U-nuts in the inner roof side rail. Tighten the screws to 6 N·m (50 in. lbs.).

NOTE: Be certain that the airbag cushion is not twisted during installation. If a colored stripe (red for right side bag, blue for left side bag) is visible on the cushion, the bag is twisted and must be untwisted before it is secured to the roof side rail.


5. Engage the two plastic push-in fasteners that secure the airbag cushion channel to the roof side rail at the top of the C-pillar.
6. Engage the two plastic push-in fasteners that secure the channel to the roof side rail at the top of the B-pillar.
7. Install and tighten the six screws that secure the airbag channel to the box nuts in the inner roof side rail. Tighten the screws to 6 N·m (50 in. lbs.).
8. Engage the hook on the end of the side curtain airbag front tether into the slot in the inner A-pillar.
9. Engage the two plastic retainers that secure the side curtain airbag front tether to the inner A-pillar.



10. Reconnect the body wire harness connector (2) for the side curtain airbag to the connector receptacle at the back of the inflator (1) on the roof side rail (3).
11. Reinstall the headliner into the vehicle.
(Refer to 23 - BODY/INTERIOR/HEADLINER - INSTALLATION).
12. Do not reconnect the battery negative cable at this time. The supplemental restraint system verification test procedure should be performed following service of any supplemental restraint system component. (Refer to 8 - ELECTRICAL/RESTRAINTS - STANDARD PROCEDURE - VERIFICATION TEST).