05-06 PCM issue is solved

MountaineerTom said:
What kind of scanner reads the 42RLE codes?

@Wranglerfix , I'm starting to get more frequent 1-2 hard shifts, but I have no codes when doing the key cycle 3 times and checking the odometer reading (it just says "done"), no codes (or pending codes) when using my OBD II and no Check Engine/Gauges lights on the dash, other than the check during initial start up. I don't know about trans codes because I don't know what to use to read them yet. It starts and runs fine as of now, other than the hard shift sometimes.

Can your PCM fix this issue considering I don't have all the codes and such?
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I have an Actron CP9690. Another way to determine if it’s your PCM is to disconnect your battery for a bit. If after you reconnect, the hard shift problem goes away, then it is highly likely that the problem is your PCM. If that’s the case, the hard shifting will return soon. Good luck.
 
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To MountaineerTom, you have exactly what I had. I had no check engine or codes either. Just the hard shifts between 1 and 2. For a while I would disconnect the battery to reboot the PCM back to it's default settings. This is the test. Disconnect your battery and turn the headlights on and off just to purge any remaining power as I understand it. Then hook back up and drive. If the hard shift is gone, it's your PCM. I went through this for some months before I came across the Wrangler Fix PCM on this site. I ordered and received it in about 1 week. My Jeep has been perfect ever since. Not all of us with this problem had any codes come up. I suggest you do the battery test and if it cures your shift problem, get the Wrangler Fix PCM. Note the battery disconnect only work for a while. On mine it would cure the shifts for about 4 days of driving. then the problem came back. Best of Luck.
 
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Peter Panagakos said:
To MountaineerTom, you have exactly what I had. I had no check engine or codes either. Just the hard shifts between 1 and 2. For a while I would disconnect the battery to reboot the PCM back to it's default settings. This is the test. Disconnect your battery and turn the headlights on and off just to purge any remaining power as I understand it. Then hook back up and drive. If the hard shift is gone, it's your PCM. I went through this for some months before I came across the Wrangler Fix PCM on this site. I ordered and received it in about 1 week. My Jeep has been perfect ever since. Not all of us with this problem had any codes come up. I suggest you do the battery test and if it cures your shift problem, get the Wrangler Fix PCM. Note the battery disconnect only work for a while. On mine it would cure the shifts for about 4 days of driving. then the problem came back. Best of Luck.
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Just a reminder that not seeing any codes is very possibly a function of what scanner you are using. They don’t all (I.e. the less expensive ones) read transmission codes. I have two Actron scanners....my first one didn’t read trans codes but my 9690 does. In any event, as you noted, if the battery disconnect cures the problem temporarily, the PCM is bad.
 
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Thanks @Rcroane and @Peter Panagakos

The battery disconnect does clear it up on mine. Just wanted to confirm about the no codes part. I have an Actron Auto Scanner Plus CP9180. I dont know if it reads transmission codes or not, I’ll have to look it up. I know I’ve had it since 2009/2010.

When I first bought the Jeep 3 years ago it did the hard shift a couple times. I tried the battery reset and it cleared it up. I think it only did it a time or two after that up until early June of this year. So I reset again then. Since early June, it’s done the hard shift 3 or 4 times.
 
My CP9180 doesn’t reads transmission codes, so I ordered a CP9690. Thanks for the info on the scanner @Rcroane

I may still not have codes but it will be nice to have an updated reader. I may give the other one to one of my boys or a friend.
 
MountaineerTom said:
My CP9180 doesn’t reads transmission codes, so I ordered a CP9690. Thanks for the info on the scanner @Rcroane

I may still not have codes but it will be nice to have an updated reader. I may give the other one to one of my boys or a friend.
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Happy to help with the scanner info. I’m pretty sure you are going to see codes P0218 and/or P0714. If you recently disconnected your battery, you won’t see the codes until the PCM re-learns its evil ways. When the hard shifting returns, the codes will return. There is no CEL with those codes.

Let us know what the scanner shows and what you do to about a replacement PCM. WranglerFix sure seems like a good option.

Good luck.
 
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Just talked with Mark over at Wrangler Fix and have ordered my replacement unit. Really nice guy. I, fortunately, do not have any signs of problems on my new to me 05 LJ with 103,000 miles. But, I am purchasing this as an insurance policy of sorts. Will be installing the new unit and pulling the old unit and putting that in a safe place. Will report back how the swap worked in a couple weeks after putting some miles on it.
 
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JRWid said:
Just talked with Mark over at Wrangler Fix and have ordered my replacement unit. Really nice guy. I, fortunately, do not have any signs of problems on my new to me 05 LJ with 103,000 miles. But, I am purchasing this as an insurance policy of sorts. Will be installing the new unit and pulling the old unit and putting that in a safe place. Will report back how the swap worked in a couple weeks after putting some miles on it.
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Never hurts to have an insurance policy, especially when it's a PCM!

Let us know how it works.
 
Rcroane said:
Happy to help with the scanner info. I’m pretty sure you are going to see codes P0218 and/or P0714. If you recently disconnected your battery, you won’t see the codes until the PCM re-learns its evil ways. When the hard shifting returns, the codes will return. There is no CEL with those codes.

Let us know what the scanner shows and what you do to about a replacement PCM. WranglerFix sure seems like a good option.

Good luck.
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Well, no codes at all when read with the CP9690.

It has shifted a little hard at least once that I remember since I last disconnected the battery on 2 June, 2019.

I'll keep monitoring.
 
MountaineerTom said:
Well, no codes at all when read with the CP9690.

It has shifted a little hard at least once that I remember since I last disconnected the battery on 2 June, 2019.

I'll keep monitoring.
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Interesting. Have you put many miles on since the last battery disconnect?
 
Talk about a depressing thread! I managed to go 9 years with my 05 and never heard about this PCM issue. So far so good on my PCM, but I was one of the lucky ones to have the OPDA issue. Now I'm always going to pay attention to my 1-2 shifts looking for this issue to pop up 😂

I wonder what the percentage of the 175,000 05-06 TJ/LJ's made actually have a PCM issue? And I wonder if its an issue across the board like with 05/06 Liberty's or other Chrysler vehicles?

WranglerFix I hope you sell these for a long long time because I plan on passing my TJ down generations someday. Thank You for making a fix!
 
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Most of the PCM issues is with electrolytic capacitors failing. I am having the dreaded NSG370 shit the bed because Mercedes didn't know how to build a transmission failure in my 05.
 
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I ordered a unit earlier this week from Mark at Wranglerfix for my 05 LJ that is experiencing these hard shifts. I have a rebuilt transmission in it as well. I will keep the group posted.
 
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Well after several attempts of trying to track down a broke wire, bad sensor or relay to solve the hard shift, starting off in what feels like 2nd gear dilemma. I just ordered a PCM from Mark at Wranglerfix
 
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