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No CEL - limp mode no issues before 4,000 rpm randomly
Stock JK TechBulletin board forum regarding issues with OE (original equipment) components of the Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) such as factory suspension parts, engine, transmission, body parts, interior fixtures and the on-board computer.
after i took apart the intake and retorqued it, the issue went from happening every day to not happening for about a month. now it's back to every day. hard to believe that's a coincidence. did a smoke test on my intake today and found no leaks. pretty careless engineering to trigger a limp mode with no fault codes or anything.
Yep, mine has done all kinds of weird things now, since the last time I tore it down it hasn't happened again. The power loss, but I know its going to happen. Reading live data on my scanner for months and months on end, every single drive, every sensor in every module......I found in the TCM module, there is basically a safe mode that mimics limp mode. Mine didn't used to set, untill after the power episode, but now it triggers the second I start the jeep (see photo), no CEL or any other warnings. I have a pre-programmed PCM on the way from FlagshipOne for $299 lifetime warranty, free shipping. I'll soon see if its the PCM itself for $1k cheaper than the dealership.
Yep, mine has done all kinds of weird things now, since the last time I tore it down it hasn't happened again. The power loss, but I know its going to happen. Reading live data on my scanner for months and months on end, every single drive, every sensor in every module......I found in the TCM module, there is basically a safe mode that mimics limp mode. Mine didn't used to set, untill after the power episode, but now it triggers the second I start the jeep (see photo), no CEL or any other warnings. I have a pre-programmed PCM on the way from FlagshipOne for $299 lifetime warranty, free shipping. I'll soon see if its the PCM itself for $1k cheaper than the dealership.
interesting detective work! i started doing the same with my bluetooth odb2 and jscan the last couple drives. i'll check the tcm limp / safe mode statuses next time i head out.
Yep, mine has done all kinds of weird things now, since the last time I tore it down it hasn't happened again. The power loss, but I know its going to happen. Reading live data on my scanner for months and months on end, every single drive, every sensor in every module......I found in the TCM module, there is basically a safe mode that mimics limp mode. Mine didn't used to set, untill after the power episode, but now it triggers the second I start the jeep (see photo), no CEL or any other warnings. I have a pre-programmed PCM on the way from FlagshipOne for $299 lifetime warranty, free shipping. I'll soon see if its the PCM itself for $1k cheaper than the dealership.
The issue for me was caused by the lower plenum as well, mine was not correctly seated, torqued or seals were bad. I reinstalled with new seals and the issue has not occurred again. I waited and drove for several days before updating this thread
Is your problem with RPM not going over 4000 still fixed?
Greetings all. I'm not 100% certain, but I now believe this problem has something to do with the electronic shifter mechanism on these vehicles.
My 2015 Jeep Grand Cherokee did the same thing. It happened three times to me. I took it to the dealer right after it happened the first time and they said it threw no codes. But then it happened twice more, and I took it back to a dealer, and they said the shifter needed to be replaced. So what I think is going on is the shifter is telling the computer that the car is in neutral and the rev limiter is kicking in. But the car isn't in neutral it's actually in drive. When I took the car in the second time, it did throw a code that the shifter needed to be replaced.
And the good news is it hasn't happened again, so I suspect they changed something in the compute/diagnostic codes to recognize this problem. Again I'm not certain, but hopefully this might help others explore a different avenue for a solution.
So is this the fix? Having same issue with 2014 Jku. Drive all day no issues at low rpms. When you step on it to pull out in traffic or on the highway about 4200-4500 rpm Jeep starts to stall if I let off it will go back no issue stay on. It and its stalls
2016 Rubicon. Read through post and suspect the following. In February I did the oil cooler pump under the intake. Now in April I am having the 4000 RPM rev limit issue. I have to date reset the computer cleared codes and most recently changed throttle body. After reading the post I decided to dive back into the intake system. Taking a break now first thing noticed was the very front intake bolt was never tightened or in his backed out. I am hopeful and suspect that is the problem all gaskets were replaced when we did the job and it was upgraded to the all metal oil cooler. Posting this to give background before posting the hopeful solution.
06-27-2022, 09:17 AM
