J Scan for tire size change - question

[JTenn]

Wife bought a new Wrangler X. I changed the tires to 37s and went to program the change using J scan. When I make the change, it takes affect and works to correct the speedometer but it disabled the driver assistance functions such as Adaptive cruise, CC, forward collision and probably other stuff. Anyone have any ideas? I've always used a tazer but figured i already have J scan and an available license so why not. Don't really feel like forking over another $350 for a Tazer.

Sponsored

 

[Andy@AAV]

How long since you updated the tire size? It could require a few cycles before the other systems update?

 

[JTenn]

Well it was immediate. It's a brand new Jeep and all these systems quit working. Kinda freaked us out a bit so I found a system restore button and that seemed to fix it. Everything is back to normal but the tire size is back to factory as well. I need toblearn more about JS. I know its a super functional tool

 

[JTenn]

It also could possibly have to do with the fact all the doors are off and I know closing the door is part of the process.

 

[BlueScapegoat]

It sometimes takes a while for the BCM to reset and everything to act normal again. A couple drive cycles or overnight sometimes.

 

[JTenn]

Thanks for the replies. I assume JS and Tazer use very similar architecture because they both seem to require the power cycles and time. Im just so unfamiliar with JS and dont want to mess something up that i can't recover from.

 

[biplaneguy]

I used Jscan to change my tire size and it took effect immediately without affecting anything else... but I have a base Sport with none of those driver assistance functions.

Jscan and Tazer work completely differently.

 

[Renegade]

It’s probably because your doors are off. I’ve used J-scan on numerous Jeeps and never had that issue.

 

[JTenn]

It’s probably because your doors are off. I’ve used J-scan on numerous Jeeps and never had that issue.

Im doing it with the doors all on right now. It sat about 20 minutes and still didn't work. Im letting it sit again and will try in a bit.

 

[JTenn]

Well, 2 long power cycles didn't work. I guess I'll try getting another Tazer. Apparently there are "some" JT's and JL's between 25.5-26 model year that experience this problem. MDH on this build is 020710. Feb, 7- 10am. Tazer supposedly has a "fix" for these builds that are affected. Maybe the dealer could be an option too. Frustrating when things dont work like they should.

 

[JTenn]

Here's a screenshot of what I found on J scan support page. Z automotive apparently has a fix for these vehicles that are affected by the faulty module that FCA wont replace. From what I can find, FCA realized there was a problem with some of the modules and corrected it but if you have a "bad" one, youre sol. I have an email out to ZA to see what they say.

 

[RCott77]

I had the same problem. I figured I accidentally unplugged something I shouldn't have while I was up under the dash. Pissed me off!! I spent hours with the drive seat out head wedged under the damn dash to see what I may have disconnected. It lasted about a week if I remember correctly.
Then one day I remote started my Jeep and it all worked. I don't know if it was the remote start or it was just time to fix itself but no issues since

Sponsored