Just put new lift on jeep and now it won't shift. Reverse works, but drive is stuck in 2nd gear. I put shifter in first and it's still in 2nd. It won't shift manually, no up or down shifting. It goes P,R,N,2 thats it. Any ideas? Also no trouble codes found. Battery was disconnected for three weeks for jeep upgrades. Tried turning it off and on, no difference. Jeep is also a early model 07 with out the transmission over heat crap programed into it. Computer has never been reflashed

 

Was it a body life? Start checking the shifter linkage and cable and shifter.

 

No it wasn't a body lift. Nothing was disconnected from trans at all. Everything looks properly connected

 

transmission is in limp home mode. (constant 2nd gear in forward)..

often thats a loss of computer communications from the trans to the PCM. id double check all the connectors and that a wire or harness didnt get knicked during lift install..

also make sure all the pins are pressed into the connectors themselves. any slight stretch of a harness or such can cause minor connection issues.. even 1 pin on the computer connector will place the trans in this mode..
-Christopher

 

Thanks Chris. I will re-check the connectors.

This wouldn't have anything to do with speed sensors would it? I just put new re-geard axles under it

 

Did you flash the computer for the new gears?

 

No I have never reflashed the computer. Don't really want to either. Was running 4.10s with 37's and now have 5.13s and 37. This should have put it pretty close to the original stock setup.

 

The computer knows the 4.10's are gone as the 5.13's don't spin the same and it faults as it thinks there is a serious problem, limp mode.

You must reset the computer to match the gears and tires or it will never go away.

Use a programmer like a ProCal or such and you will be fine.

 

My Jeep JK 2014 w/37s, auto tranny, 4.88 gears & Supercharger wouldn't shift yesterday after an hour of chasing a Razer and LS1 Jeep around Ocotillo Wells. I had the tire pressure down to 15 psi. It wouldn't shift using the auto shifter mode either by moving the shifter left and right. Engine light came on but I didn't have a code reader. Tranny oil temp was reading 221F.


Made it back to the RV resort, keeping the RPMs below 4K. After a beer and dip in the pool, aired up the tires and started the drive back home. Tranny temp 172 F, Check engine light went out and it shifted normally.


I've read the computer knows the 4.10's are gone as my 4.88’s don't spin the same and it faults as it thinks there is a serious problem, limp mode. You must reset the computer to match the gears and tires or it will never go away. Use a programmer like a ProCal or such and you will be fine.



Questions:

1. Is there a way to check the error code history?
   
2. Is there a way to know if the computer has been reflashed to reflect the correct gearing?
   
3. If not should I try to reset the computer to match the gears and tires? I assume this was done but not sure.
   
4. Any details on how to reset the computer?
   

I don't plan on running with Razers anymore. LoL.

 

Limp mode would light the MIL wouldn't it? I'm new to Jeeps.