question about larger diameter tires

[Tony]

is there any remaping of the ecu required when changing to a larger diameter tire for the kj? when i put my 32's on my f150 it threw off the speedometer and my ****** shift points which caused ****** problems for me down the road and i dont want to fall into the same trap with the libby.

 

[04Liberty]

A dealer can flash your PCM for the change in tire size. Unfortunately no one ever offered a programmer for the KJ.

 

[Tony]

A dealer can flash your PCM for the change in tire size. Unfortunately no one ever offered a programmer for the KJ.

thanks for the insite. i didnt see anyone here mention it so i didnt know if it was nessary.

 

[Ry' N Jen]

I you do a search on the site here...
Plenty of info regarding it!
http://www.jeepkj.com/forum/search.php?searchid=800298
It's called a Pinion reset.
I took our Heep into the dealership and they didn't know that they could even do it!
Long story short, it was done for free!

 

[Tony]

p:

I you do a search on the site here...
Plenty of info regarding it!
http://www.jeepkj.com/forum/search.php?searchid=800298
It's called a Pinion reset.
I took our Heep into the dealership and they didn't know that they could even do it!
Long story short, it was done for free!

thanks for the info! i would never of thought to look under pinion reset, gess thats why i couldnt find itp:

 

[tjkj2002]

Only can be done on some years and some years that it can be done only some tire sizes can be plugged in(all OEM stock tire sizes).

If your lucky and it can be done it drastically helps in shifting.

 

[HoosierJeeper]

I think 05 was the last year that they could do it IIRC.

 

[Tony]

oh, that *****. do you know what years? mine is an 03

 

[Ry' N Jen]

It made a big difference for our Heep!
Shifts like stock now...
We will see if it can be done once again when
I go to 32/33 inch tires next year!

 

[Tony]

It made a big difference for our Heep!
Shifts like stock now...
We will see if it can be done once again when
I go to 32/33 inch tires next year!

thats good to hear. i have an 03 do you think it could be done on mine?
thanks again for your help.

 

[Ry' N Jen]

thats good to hear. i have an 03 do you think it could be done on mine?
thanks again for your help.

That all depends on where you take it for one!
If you take it to a dealership they should be able to do it.
You need to know the Revolutions per mile/Kilometer
ie. 245-75-16 tires= 661.93/411.06
I use this tire calculator. I find it very handy for this reason...
http://www.csgnetwork.com/tireinfo4calc.html

 

[Tony]

That all depends on where you take it for one!
If you take it to a dealership they should be able to do it.
You need to know the Revolutions per mile/Kilometer
ie. 245-75-16 tires= 661.93/411.06
I use this tire calculator. I find it very handy for this reason...
http://www.csgnetwork.com/tireinfo4calc.html

awsome!!! thats just what i needed!

 

[rockymountain]

Only can be done on some years and some years that it can be done only some tire sizes can be plugged in(all OEM stock tire sizes).

If your lucky and it can be done it drastically helps in shifting.

x2
helped shifting on mine. It almost felt like I put the old tires back on after a while. I gave the dealer the rev per mile spec for my tires and they plugged it in. I went from reading about 6 over on the highway to within 1 mph of what my GPS said. Cost me $25.