Novak Conversions Jeep Wrangler TJ engine mounts

Interesting read on the 05-06 PCM for the 42RLE with potential help for one limp problem.

Jerry Bransford

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Recently posted by MFilippello on a different forum for those with the 42RLE on an 05-06. This is one of the reasons for my usual recommendation to avoid 05-06 TJs, especially if it has the 42RLE transmission.

At least this includes a potential fix for at least the issues described below...

"Hello everyone. I figured i would throw my hat into the ring. I have a 2006 unlimited rubicon auto. I too have been dealing with PCM issues. I was getting the dreaded U0101 (lost communication with TCM) and P0714 (intermittent trans temp code) and P0218. About once a week it would get stuck in 2nd gear (limp mode). Learning these were symptoms of a bad PCM, I started calling many places looking for a replacement PCM from a reputable supplier. I even put a back order with Jeep only to find out the part has been discontinued. After calling dozens of places, the reputable ones told me that once the PCM has TCM issues, it is not repairable. This is because the repair involves replacing the TCM chip on the board which no one can do.

Knowing someone was doing the refurbs for Mopar, I kept digging and found the company. I spoke to the head technician to find out why they stopped supplying refurbs to Mopar and why no one can fix these units. According to him, they tried sending the bad PCMs (PCM's with transmission issues) out to a 3rd party to have the TCM chips replaced with chips from donor boards(Evidently there is no source for new TCM chips so I guess they were cannibalizing parts from multiple boards). In order to do this requires a wave tank to remove and re soldier the replacement chip to the board. They had to outsource this procedure to a company with the necessary equipment. The success rate was only 50-60% from what he told me so this is why they stopped. Keep in mind, this was only to fix PCM's that had Trans issues as they can fix other issues related to these PCM's (ie o2 sensor codes etc.)

While I was talking to him, he told me they had had some success applying pressure to the case while testing it on their equipment. They have all the factory Mopar test equipment to diagnose these PCM's. I asked what he thought of putting something between the cover and the gel over the area where the TCM chip resides that would apply pressure once the lid was screwed back on. He said they had actually done that on a PCM with success. Since I had nothing to lose, I decided to give it a try. I gently pulled the cover off and used a heat gun to get the sticky gel to release from the rubber tabs that protrude from the backside of the lid along the top.

I noticed that when i unscrewed all the screws holding the cover on, that the top left started to separate on its own. This is where I started pulling the cover off. After getting the lid completely off I tried to lay it back down to see why the top left wouldn't lay flush. Something was causing it to stick up. After looking at it a bit I noticed that some of the rubber tabs that extend through the gel line up with chips and others line up on bare pads where no chips are installed. The longer rubber pads lined up with bare spots and the shorter pads lined up with locations that had chips. This was the case for all the tabs except two spots on the top left corner. There were two tabs that were long yet fell on spots that had chips. This was what was causing the lid to not lay flush. This seemed wrong to me as it would cause undue pressure on the board once the lid was forced closed with the screws. So I took a knife and trimmed these two tabs down even with the other short tabs. This allowed the cover to now lay flat as it should.

Figuring this may have been causing the board to flex it was worth a try to reinstall after just doing this fix. So far it has been 3 weeks and the jeep is running fine with no codes or issues(knock on wood) I don't know how long this will hold up but it is an easy thing to try as it does not require all the work removing the board from the case or removing any of the gel. Just slowly lift the lid while applying heat to help the gel release from those rubber pads. Once the lid is off, you can check if your lid has similar tabs that are cut to the wrong length and trim accordingly. I will try and post updates if things stay good or if problems return.

this is a really shitty situation for all of us with 05-06 jeeps. From everyone I spoke to, the only solution to this issue is to find a used auto PCM that doesnt have the trans problem yet or get lucky swapping pcm's from these refurb companies until you get one that was refurbed for an issue other than TCM problems. It is only a matter of time till they all die unless Mopar makes new ones or somebody can find a source for the original TCM chips and also find a way to replace them without damaging the board. To be honest, before I shell out $1500 for a used PCM, I will put that money toward a LS swap. That seems the more likely long term solution. Screw you Mopar."
 
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So, in essence, all these guys buying LJR's as investments are either going to REALLY make bank as the PCM supply dries up or they have thrown their money into a losing proposition...
 
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So, in essence, all these guys buying LJR's as investments are either going to REALLY make bank as the PCM supply dries up or they have thrown their money into a losing proposition...
It's not just the LJR, it's any 05-06 4.0L with the 42RLE.
 
Several members of the other Jeep Wrangler forums who own 05-06 TJ's and who have experienced hard shifting in their 42RLE transmissions that can be traced to a faulty PCM have obtained refurbished PCM's from this Florida company and have reported no further issues after driving several months and thousands of miles:

https://modulegods.com/


While there is no question that hard shifts from 1-2 when the 43RLE transmission is cold is a documented issue that can be traced to a small percentage of the PCM's manufactured for the 05-06 model years, it is by no means widespread and therefore not a principled reason to categorically avoid altogether 05-06 Wranglers with the 4-speed automatic. Statistically it is an issue that is too infrequent to warrant a recall or TSB of any kind and apparently not of sufficient frequency to justify to FCA management any further effort or expenditure.

Fortunately there is a third party commercial source for a long term fix that will keep the 05-06 Wrangler owners with the issue on the road. Another option is to warm up the engine and transmission before starting off and the hard shifts won't manifest. It may not be a fix but it is a workaround that costs nothing.
 
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It's not just the LJR, it's any 05-06 4.0L with the 42RLE.
Right, but you don't generally see the ridiculous prices for a SWB TJ Rubicon like you do for the LJ Rubicons. Somewhere, someone decided that it was the ONE to collect...seems every add I see for them now stresses their rarity over anything else.
 
I would caution anyone considering purchasing from Modulegods to research the company and the owners, and educate themselves on who they are purchasing from. The idea of someone in the aftermarket manufacturing a new PCM for our jeeps is certainly attractive and I felt it was worth the significant premium in price over FS1. Unfortunately while some have reported success, it's not guaranteed. The true test of a company and it's customer service is not how well it takes your money and process your order, it's how it conducts itself when there is a problem.
 
Recently posted by MFilippello on a different forum for those with the 42RLE on an 05-06. This is one of the reasons for my usual recommendation to avoid 05-06 TJs, especially if it has the 42RLE transmission.

At least this includes a potential fix for at least the issues described below...

"Hello everyone. I figured i would throw my hat into the ring. I have a 2006 unlimited rubicon auto. I too have been dealing with PCM issues. I was getting the dreaded U0101 (lost communication with TCM) and P0714 (intermittent trans temp code) and P0218. About once a week it would get stuck in 2nd gear (limp mode). Learning these were symptoms of a bad PCM, I started calling many places looking for a replacement PCM from a reputable supplier. I even put a back order with Jeep only to find out the part has been discontinued. After calling dozens of places, the reputable ones told me that once the PCM has TCM issues, it is not repairable. This is because the repair involves replacing the TCM chip on the board which no one can do.

Knowing someone was doing the refurbs for Mopar, I kept digging and found the company. I spoke to the head technician to find out why they stopped supplying refurbs to Mopar and why no one can fix these units. According to him, they tried sending the bad PCMs (PCM's with transmission issues) out to a 3rd party to have the TCM chips replaced with chips from donor boards(Evidently there is no source for new TCM chips so I guess they were cannibalizing parts from multiple boards). In order to do this requires a wave tank to remove and re soldier the replacement chip to the board. They had to outsource this procedure to a company with the necessary equipment. The success rate was only 50-60% from what he told me so this is why they stopped. Keep in mind, this was only to fix PCM's that had Trans issues as they can fix other issues related to these PCM's (ie o2 sensor codes etc.)

While I was talking to him, he told me they had had some success applying pressure to the case while testing it on their equipment. They have all the factory Mopar test equipment to diagnose these PCM's. I asked what he thought of putting something between the cover and the gel over the area where the TCM chip resides that would apply pressure once the lid was screwed back on. He said they had actually done that on a PCM with success. Since I had nothing to lose, I decided to give it a try. I gently pulled the cover off and used a heat gun to get the sticky gel to release from the rubber tabs that protrude from the backside of the lid along the top.

I noticed that when i unscrewed all the screws holding the cover on, that the top left started to separate on its own. This is where I started pulling the cover off. After getting the lid completely off I tried to lay it back down to see why the top left wouldn't lay flush. Something was causing it to stick up. After looking at it a bit I noticed that some of the rubber tabs that extend through the gel line up with chips and others line up on bare pads where no chips are installed. The longer rubber pads lined up with bare spots and the shorter pads lined up with locations that had chips. This was the case for all the tabs except two spots on the top left corner. There were two tabs that were long yet fell on spots that had chips. This was what was causing the lid to not lay flush. This seemed wrong to me as it would cause undue pressure on the board once the lid was forced closed with the screws. So I took a knife and trimmed these two tabs down even with the other short tabs. This allowed the cover to now lay flat as it should.

Figuring this may have been causing the board to flex it was worth a try to reinstall after just doing this fix. So far it has been 3 weeks and the jeep is running fine with no codes or issues(knock on wood) I don't know how long this will hold up but it is an easy thing to try as it does not require all the work removing the board from the case or removing any of the gel. Just slowly lift the lid while applying heat to help the gel release from those rubber pads. Once the lid is off, you can check if your lid has similar tabs that are cut to the wrong length and trim accordingly. I will try and post updates if things stay good or if problems return.

this is a really shitty situation for all of us with 05-06 jeeps. From everyone I spoke to, the only solution to this issue is to find a used auto PCM that doesnt have the trans problem yet or get lucky swapping pcm's from these refurb companies until you get one that was refurbed for an issue other than TCM problems. It is only a matter of time till they all die unless Mopar makes new ones or somebody can find a source for the original TCM chips and also find a way to replace them without damaging the board. To be honest, before I shell out $1500 for a used PCM, I will put that money toward a LS swap. That seems the more likely long term solution. Screw you Mopar."

Thanks for share this @Jerry Bransford .

I have been reading and gathering info about this issue for some time. This point different fix to a problem every 05-06 42RLE person explain differently.
 
While there is no question that hard shifts from 1-2 when the 43RLE transmission is cold is a documented issue that can be traced to a small percentage of the PCM's manufactured for the 05-06 model years, it is by no means widespread and therefore not a principled reason to categorically avoid altogether 05-06 Wranglers with the 4-speed automatic. Statistically it is an issue that is too infrequent to warrant a recall or TSB of any kind and apparently not of sufficient frequency to justify to FCA management any further effort or expenditure.

I'm a little confused by this, there is a TSB regarding hard shifts on first start in the 42RLE and several of us are running the revised program that was issued with the TSB to correct this issue. It isn't limited to 05-06 or to Jeep vehicles. The problem Jerry posted is about a TCM failure which is very severe compared to the 1-2 shift issue.

There isn't likely to be a shortage of good TCMs for any year TJ/LJ. There are few that suffer this problem and many more that are crashed or rust out and end up in junkyards with good computers.

I wouldn't expect Jeep to make new black boxes for any vehicle this old, I didn't think any manufacturer did regardless of problems.
 
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Thank goodness that manual transmissions are not directly effected by electrical engineering blunders. But...
 
. . . there is a TSB regarding hard shifts on first start in the 42RLE and several of us are running the revised program that was issued with the TSB to correct this issue. It isn't limited to 05-06 or to Jeep vehicles. . . .

Do you have a link for that TSB?

The threads in the other TJ forums concerning the 1-2 hard shifts in some 42RLE's are all over the map and contain a substantial amount of misinformation as well as conflicting statements. One has to read all of them and read them carefully to recognize the difference between new information, personal bias, and frequently repeated Internet myth. I have read several times in those threads that there is no TSB related to the PCM issues at the root of some of the 1-2 hard shifting issues. I have also read that there is a TSB sometimes described as directly related and sometimes described as relating to a similar but different problem but with no link to the document itself.

I do not want to repeat incorrect information and would really like to read that TSB. I do not have the hard shifting issue with my '06 LJ with 42RLE and hope I never do. [Knock on wood.] Nevertheless I would like to have the best and most current information available "just in case."

P.S. - I agree with you that there are probably enough perfectly good 05-06 PCM's in the auto boneyards to replace many times over the number of faulty PCM's. The fix may be a hassle, and not inexpensive, but no reason to go all Chicken Little about every 05-06 TJ with an automatic transmission ever built.
 
Novak Conversions Jeep Wrangler TJ engine mounts