RHD 06 keeps triggering limp mode

[Jerry Bransford]

05/06 TJs with automatics have a serious problem with the transmission control module which was integrated into the PCM beginning in 05. The TCM can get so hot inside the PCM it can literally blow like an M80 firecracker blew up inside. That'll cause major problems for the 42RLE transmission.

Installing a new OEM or used replacement PCM is only a temporary fix, it's likely to just blow again.

@Mark cantrell at www.wranglerfix.com has come up with a different direct replacement Chrysler PCM that is a permanent fix for that problem if that's what has happened to your PCM. I'd give him a call (he's also a member here) and talk your issues over with him. He has a fleet of different model year TJs and can test yours to see if it's really bad. Or just send you the replacement if you and he agree it definitely sounds like a bad PCM.

 

[TrowaB]

05/06 TJs with automatics have a serious problem with the transmission control module which was integrated into the PCM beginning in 05. The TCM can get so hot inside the PCM it can literally blow like an M80 firecracker blew up inside. That'll cause major problems for the 42RLE transmission.

Installing a new OEM or used replacement PCM is only a temporary fix, it's likely to just blow again.

@Mark cantrell at www.wranglerfix.com has come up with a different direct replacement Chrysler PCM that is a permanent fix for that problem if that's what has happened to your PCM. I'd give him a call (he's also a member here) and talk your issues over with him. He has a fleet of different model year TJs and can test yours to see if it's really bad. Or just send you the replacement if you and he agree it definitely sounds like a bad PCM.

It has a wrangler fix PCM in it. I did that last summer.

 

[TrowaB]

Did you go through and check the wiring according to the FSM? It tells you what to replace depending on where it fails during the testing.

I checked continuity on every wire that goes to the transmission today. All were fine from the plugs to the PCM as well as the ones that go to the relay. I also checked the ones running from the C4 plug on the pcm to the relay and ground.

 

[TrowaB]

Part of what makes me want to change the valve body (other than the fact it won’t stay out of limp) is that I found this 2/4 accumulator piston had a big scar on it.

 

[Shafti]

I am having a 2004 Tj, and I do have the same issue with my transmission, I have worked on my wires recently ending up having a full new harness, the gear started triggering the limp mode at the beginning when I cam to know that some of the wires at the input speed sensors were a bit lose, I 've reconnected them and have done a hard reset through the battery and everything was well, after that had some issues with the temperature sensor the gauge wasn't stable while I knew the engine cooling system was running fine so I ignored it, now my gear is stuck again in limp mode and have done almost everything so fight the code of P0700 which is the only code that I have but yet I am not reaching any where.

If you do have a remedy for this can you please share with me, It's been a very long time since I started this journey

 

[rlinares40]

I am having a 2004 Tj, and I do have the same issue with my transmission, I have worked on my wires recently ending up having a full new harness, the gear started triggering the limp mode at the beginning when I cam to know that some of the wires at the input speed sensors were a bit lose, I 've reconnected them and have done a hard reset through the battery and everything was well, after that had some issues with the temperature sensor the gauge wasn't stable while I knew the engine cooling system was running fine so I ignored it, now my gear is stuck again in limp mode and have done almost everything so fight the code of P0700 which is the only code that I have but yet I am not reaching any where.

If you do have a remedy for this can you please share with me, It's been a very long time since I started this journey

have you checked to make sure you have the right amount of fluid in the transmission? i've run into the issue where i was 1-2 quarts low and it would put the vehicle in limp mode (auto transmission).

 

[Shafti]

have you checked to make sure you have the right amount of fluid in the transmission? i've run into the issue where i was 1-2 quarts low and it would put the vehicle in limp mode (auto transmission).

I did actually, fluid level was maintained and I have also checked for any issues in the connection that I never found anything, I did my research as I have found that a bad temperature sensor can cause the limp code, recently my temperature gauge was super unstable which made me think that it's wiring problem, I have worked on the connector and managed to get a stable reading again, I tried to erase the the P0700 but wasn't really working, the code kept on showing back.

 

[macleanflood]

I'd probably call Mark @Wranglerfix wranglerfix.com

-Mac