Daniel,

I personally find it difficult to believe that these sensors would be mounted to the bumper. I don't own a Jeep so can neither confirm nor deny this specifically but, in general, a bumper mounted sensor seems unlikely. A more likely location would be somewhere else near the front of the crumple zone. In my vehicle, the sensors are mounted to the lower frame rails. In other vehicles, the sensors are attached to the radiator frame. That being said, the original post that started this thread was asking two questions:

1 - What keeps the airbag from deploying while undergoing extremem four-wheel
drive conditions?

I found this information addressing that question:

"Air bags are typically designed to deploy in frontal and near-frontal collisions, which are comparable to hitting a solid barrier at approximately 8 to 14 miles per hour (mi/h) (13 to 23 km/h). Roughly speaking, a 14 mi/h (23 km/h) barrier collision is equivalent to striking a parked car of similar size across the full front of each vehicle at about 28 mi/h (45 km/h). This is because the parked car absorbs some of the energy of the crash, and is pushed by the striking vehicle." (source :http://en.wikipedia.org/wiki/Airbag)

My point is, if you are 4-wheeling and experience the equivalent of hitting a solid barrier at greater than 8 mph, chances are you have *actually* hit a solid barrier at greater than 8mph and in that case you should be grateful that your air-bad deployed. ;-)

2 - Can the airbag be safely disabled? If so, how?

Most likely it can be disabled. Check your repair manual (not your owner's manual.) It should describe how to disable your air bag system while performing related maintenance. Keep in mind, as someone mentioned earlier, it may be illegal to disable an air bag system except for maintenance purposes. I'm not convinced this is precisely true but then, I'm not a lawyer. I do know it is illegal to *sell* a vehicle that has had the air bag purposely disabled. This applies to dealers and individual sellers alike.

I have a 1998 Cherokee Sport with the 4.0 engine. The airbag light keeps
coming on and off, sometimes for a long while, other times not long at all.

If your Jeep has "smart" or "advanced" air bags, there may be sensors located in the seats and seat belts designed to detect the weight of the person sitting there. I don't know if these were available in '98 but I've read that the early designs did have problems properly detecting the weight of a person and they would sometimes cause the "Airbag Off" light to come on intermittently if there was a small person in the passenger seat, if they were sitting in an unusual position or if sudden movements of the vehicle caused them to shift positions in the seat. It's also been reported that seat covers can also affect the sensors of these "smart" systems.

Lastly, your vehicle ('98 Jeep Cherokee) did undergo a safety recall for "Airbag Control Module Internal Corrosion" in May of 2000. You may want to check with your local authorized Jeep repair facility.

-- Sprocket

Please forgive my ignorance here, what happens to these guys who replace the 
factory bumber with a bumper that can actually be useful to jeepin'? Are the 
sendors in the bumper mounts?

Daniel




---------- Original Message -----------
From: "Raphaella Emet" <khofesh@comcast.net>
To: <listserv@azgeocaching.com>
Sent: Thu, 1 Sep 2005 17:49:51 -0700
Subject: RE: [Az-Geocaching] OT: Jeep question

> Most vehicles have the airbag sensors in the bumper. There have been
> accidents where the bumper of the vehicle wasn't hurt even though the
> vehicle was toast and the airbags never deployed because the sensors 
> didn't get the impact.
> 
> VeloRacer