Weird Service 4WD Gremlins

[At Risk Ute]

‘21 JLR 2.0T w/ 25K miles. Service 4WD light came on in when we shifted to 4L and lost lockers. Had to bail on our EJS trail and it was tough getting the transfer case out of 4L. Other lights that fired were the Sway Bar! and Traction Control ones.

Kept getting weirder on pavement in 2H. Would shift into 6th gear and gas pedal did nothing. Kept having to manually downshift.

Jeep sat for a night and tranny is back to normal. Drove fine on the interstate.

Get home tonight and decide to check everything in the gravel. Lockers now work. Only issue now is rear tires’ TPMS are lit up despite being the same psi as the front.

Any ideas? Wonky different shit happened on Cliffhanger last June. My only guess is steep inclines and declines.

I’m sick of the delicate JL electronics. 4L should be bulletproof.

I'll look for codes mañana, but dealer will never be able to replicate. Was fixing to wait until the warranty expired, but fuck this.

Atlas transfer case and Ox lockers?

Sponsored

 

[mwilk012]

Sounds like a transmission problem, no amount of 4wd faults should ever cause a 6th gear ratio failure. Obviously the first step here is to pull the saved codes.

 

[At Risk Ute]

U1440 so DTCM. Found a TSB.

https://static.nhtsa.gov/odi/tsbs/2020/MC-10181618-9999.pdf

 

[GreenWilly]

The JL 4wd system is a technology nightmare. It uses inputs from your wheel speed sensors, FAD, transfer case, DTCM, transmission, and on rubicons the electronic locker harness. The traction control system is showing multiple faults and is putting your computer in limp mode when you switch into 2H. Could be the locker harness, a bad ground, wheel speed sensor, or if you use the Tazer JL a corrupt file. The DTCM reprogram may also help. I have this issue on my wife's jeep since installing the gears and ARB locker. Everything works, only thing I need to do is turn the vehicle off and back on once in 2H.

 

[At Risk Ute]

The JL 4wd system is a technology nightmare. It uses inputs from your wheel speed sensors, FAD, transfer case, DTCM, transmission, and on rubicons the electronic locker harness. The traction control system is showing multiple faults and is putting your computer in limp mode when you switch into 2H. Could be the locker harness, a bad ground, wheel speed sensor, or if you use the Tazer JL a corrupt file. The DTCM reprogram may also help. I have this issue on my wife's jeep since installing the gears and ARB locker. Everything works, only thing I need to do is turn the vehicle off and back on once in 2H.

Great insight. Yeah, started happening now that I come to think of it after installing 4.88 gears.

 

[GreenWilly]

It's got to be a programing issue. When I was pulling my hair out trying to track it down, my codes would be for wheel speed and transfer case output not matching. I gave up and just let it ride.

Sponsored