Are there any concerns with the airbags and sensors when switching out bumpers? This wasn't really an issue with my last jeep, but it occurs to me that my Jk is a modern vehicle, regardless of how much is like to think otherwise.

 

No issues. The airbags work of an accelerometer that is located in the center of the vehicle under the center console. There are no contact style sensors so you will be fine.

 

Perfect. Thanks for the info.

 

There has to be an impact sensors. All airbags systems has to have that information. There are always a acceleration/deceleration sensor but it cant take place of an impact sensor.

 

I've got impact sensors behind or in close proximity to the headlights as should everyone else even if you haven't noticed them. They'll be yellow as all air bag related items are so that you knew what you're dealing with.

The only *concern* you'll have with an aftermarket bumper is that it will soak up more of the load than a stock bumper because the stock bumper is designed for a controlled crush as well as pedestrian safety, minimum impact for low speed accidents, etc. Your new shiny steel bumper will not have any forgiveness for whatever you may encounter. The exception to that would be any bumper that only bolts through the 8 holes in the shoehorns on the end of your frame. Obviously there's a weak point there and it will move more than if you tie it into your frame rail and/ or crash bar. This is experiencing talking, not interwebs knowledge.

 

Good to know. Thanks!

 

It sounds like you are thinking there is a difference between an accelerometer and an impact sensor.

On the JK, "impact sensor" and "acceleration/deceleration sensor" are terms that describe the same thing.

This is from a factory service manual description of what's up front:

"The front impact sensors are electronic accelerometers that sense the rate of vehicle deceleration, which provides verification of the direction and severity of an impact. Each sensor also contains an electronic communication chip that allows the unit to communicate the sensor status as well as sensor fault information to the microprocessor in the Occupant Restraint Controller."


There are two accelerometers in the module on the tunnel between the front seats, and one accelerometer on each side for those with seat airbags.

Regarding changing bumpers with respect to the airbag system...

The stock front bumper has two crush cans. They are designed to slow the deceleration of a small impact.
Without them, the same small impact on an aftermarket bumper may be enough of a shock to set off the airbags.
Additionally, the crush cans probably prevent the collapsible front frame rails from folding in a small frontal impact.
It seems the crush cans are Jeep's effort to have a 5 mph bumper, and still be able to have recovery hooks on the bumper.

 

Mind you most of the Jeeps I've worked on were dirty but I've had the area behind my lights taken out many times and never seen this ... What year is yours and where are they exactly?

 

I'll be under the hood tomorrow so I'll get better descriptions for you but they're up by/ behind the headlight buckets, kinda down towards the bottom. This is on my 10 but I've seen the same from 07's- 15's.

 

The front impact sensors are on the back of the headlight supports, just inboard of each headlight, viewable from behind the headlights.