My 2012 Jeep JK is popping 5 codes, P0501, U0101, U0121, U1409, and U140A. I am running a 2 1/2in lift with 35's that has been installed for a year with no issues. I have ensured my steering wheel is centered and my front end is aligned. It started after going to an off-road park, was about 15 minutes down the road when my ABS light and ESB light came on. About 5 minutes further my brake light came on and would sporadically engage. I would stop, brakes would fully engage. I would turn it off and it would reset my breaks and the lights. After 1/2 hour down the road my check engine light came on. that's when I decide to check my steering wheel alignment and it was off a slight bit so I corrected it and cleared the codes. It stayed off for about 1/2 hour then it all came back with the hill assist flashing at first. I stopped and turned the engine off. Turned it back on and the ESB would start to cut the throttle to my engine until I turned off the ESB. I am running out of ideas of what could be causing my problems. I haven't modded the ABS/ESB system either.

 

Check your vss sensors, they should be located in the axels, I think the rear is above the pumpkin if what I saw yesterday when I was checking something underneath was the speed sensor. They migth get dirty as crap if you were mudding, disconnect them, clean them real good, plug them back and reset the battery.
Good luck.

 

Speed sensors are located at each wheel, not at the differential. The sensors are sealed units but debris can accumulate and cause the readings to skew.

Have you googled each code to see what comes back?

 

Thanks for the clarification, still getting to know where things are located in the JKs.
So how do we replace the sensors if they' re sealed?

 

disregard

 

Those codes look like wheel speed sensor faults.
When you did your lift did you make sure the ABS wires were free? The last two codes I think are the front left and right sensors.

 

Ive googled what each one is:
P0501 - Vehicle speed sensor 1 performance
U0101 - Lost communication with TCM
U0121 - Lost communication with anti-lock brake module
U140A - implausable RH front wheel speed signal recieved
recievedimplausable LH front wheel speed signal recieved

The first 3 are from the internet/my code reader, last 2 are from my code reader and haven't seen them online and ive looked. I cant go to any major auto parts center due to being in the UK (LH drive). I am going to take it in to put it on a lift so i can tear into hubs and clean them

 

Ive googled what each one is:
P0501 - Vehicle speed sensor 1 performance
U0101 - Lost communication with TCM
U0121 - Lost communication with anti-lock brake module
U140A - implausable RH front wheel speed signal recieved
recievedimplausable LH front wheel speed signal recieved

The first 3 are from the internet/my code reader, last 2 are from my code reader and haven't seen them online and ive looked. I cant go to any major auto parts center due to being in the UK (LH drive). I am going to take it in to put it on a lift so i can tear into hubs and clean them

 

The rears are easy, they unclip at the back of the brakes where the e-brake cable goes in (you'll see the connector) and the fronts require more work to get to but is relatively the same process.

Rears are just the sensor, about the length of a popsicle stick, that get replaced. Fronts are the sensor plus wiring harness that goes up to the top of the framerail. The sensors are relatively cheap ~$20.


They can be cleaned and I tried to clean mine but the ultimate solution was replacement.

To the "lost communication" codes- I wish I could point you to where to look but I can't.

 

So i was able to tear apart the left hub. The sensor and hub were still good and after install was having the issue still. Didnt drive long enough to see if i still have the issue but if i do its got to be either the ABS Module or TCM. the worst part is finding out which one! Any suggestions?