i swapped a front and rear rubicon axle (2015-2016) in to my 2012 JKU. i made the rookie mistake of putting the jeep in gear before i flashed the computer with my flashcal. now the jeep is stuck in limp mode. took it to the dealer ship and they said they can change the gear ratio. but i had them reset all codes i flashed the jeep without moving it but i still get put in limp mode. the dealer is trying to tell me i have internal transmission issues (p0733, p0734.) they also are telling my my trans fluid smells burnt.

what should my next step be?

 

Are you sure or the gear ratio of the axles, they could be either 4.11 or 3.73.

 

it has 4.11 gears in the front, I have not confirmed the rear. but i can do that later today.
these were purchased form a salvaged rubicon. and the I had to get a new front housing but I have not opened the rear.
i did have to replace one of the wheel speed sensor if that is relevant.

 

if you r gonna open the rear to check the gear ratio just jack up a wheel, spin it once and count the driveshaft rev, if its a rub should be 4.10's

 

It has 4.11 gears both front and rear
However removing only one rear abs/wheel speed sensor did solve the issue... but not i have traction control and abs lights on my dash.

I unplugged left rear abs/wheel speed sensor, it drove fine. plugged it back in and limp mode... unplugged it and drove fine. same issue with the rear right.
simply it will go into limp mode with both plugged in,
It will drive fine with only one plugged in any suggestions from here?

 

Do you still have the original axle? Swap the speed sensors from it, maybe there is a difference in sensors between the years.

 

Just to add to Jeff's comment - I recently changed out my front unit bearings and of course new speed sensors came with it. I was going to use the original sensors but they were physically different in length and were too long to go into the mount hole. So I was forced to use the new ones and because they were different I fully expected to see a code and ABS system not work but to my surprise they have been working perfectly. So the OP here may have to go with Jeff's advice and at least get the right speed sensors as part numbers vary from some years to others. This I determined from Rock auto's listings.

 

I literally just did what you did to my 2012 JK using 2015 Rubi axles only I reused the wheel speed sensors that were on my original sport axles. To me, it sounds like you have correctly isolated it to a wheel speed sensor issue. I have had no problems after my swap; so there is hope for you to get to where I am at very soon! To this end, if you had the 3.23 gears originally, you too are going to LOVE the 4.11's! I am currently running the fake 33's (e.g., 285s) and am loving how it feels like it has more power everywhere in the RPM range! This kind of has me rethinking going to 35's immediately... The one thing weighing on me is that I lost 1" of clearance from the ground to the bottom of the front pumpkin on the D44 vs the D35 I had stock. Everywhere else I gained 3" from the 2.5" Terraflex springs I added when I installed the axles. You are on the home stretch after all that work you did to swap the axles!

 

I am really at a loss now I reset the ecu and the gears came back as 3.21 it was previously set at 4.11. I am not sure if that means that it never took the new flash or if it just reset to factory from an ecu reset.
But either way all that i get is code p0733. The jeep is currently drivable with one speed sensor unplugged but nothing seems to help. I am curious if it can be a locker? or if the 3rd gear solenoid is messed up.
Current plan is to install the old axle. and see if it will act normal.

Not convinced but running low on ideas.

 

I will try this week end to pull the part and compare the part numbers and order the same ones.