42RLE shifts hard from first to second

Fletch2

Member
Joined
Jun 26, 2019
Messages
28
Location
Chattanooga, TN
Hello,

This is my first post. I just purchased a 2006 TJ with only 47,000 miles. My wife and I are loving it! It’s been running great with no worries. Today, my wife drove it to work with no issues. This evening, we jump in to run to the store and the first two or three times the Jeep shifted from first to second we’re really hard shifts. After the first few shifts everything was normal. Leaving the store the same thing happened. The first few shifts from first to second were really rough then all was fine. Does this seem worrisome to anyone but me? Thanks in advance!

Oh, I have an X package with the 6-cylinder engine and 42rle tranny.
 
Sounds like you have the PCM problem that effects the 05 and 06 TJs. I do too. The solution is to replace the PCM which I am doing as soon as my new one arrives. There is a relatively recent post about a fix for this, company that is building replacement PCMs. Here is the test, disconnect your battery, turn the lights on and off, reconnect the battery. If the hard shift is gone you will know its the PCM. On mine this "reboot" will work for about 4 to 5 days. Then the hard shifts come back.
 
Yes, I also found this reset in another discussion and tried it. It worked, no more hard shifts. What company is making the replacement? Another discussion talked about having the dealer flash the PCM with an update that fixes the issue. And yet another discussion talked about getting a remanufactured unit from the dealer that would have the updates. Does anyone have knowledge of which option works the best?
 
Forgot to give you all the info, see a post called "05-06 PCM issue solved",it's on page 4 right now. I don't know yet if the new PCMs will work, but I will post my results after I install and drive my TJ for a while. I know this problem bugs. I've dealt with it for a while now. Of course, check your fluid level and condition, but I'll bet its the PCM
 
Re-manufactured PCM’s are no longer available from dealers. Chrysler has classified the part as NS1, which means they no longer support it.