42RLE Occasional Hard / Delayed Shift

julietpapa

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Joined
Apr 12, 2023
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3
Location
FL
I have an '06 TJ (automatic) with around 120k on it. Every once in a while my transmission will act up and shift late and hard in the early gears. This issue may last for a few days up to a week or so and then the issue will vanish for weeks or even months and all is smooth.

When it's acting up, it will rev much higher than normal in 1st gear, well past the usual shifting point and then jerk into the next gear. It's only through the first couple gears...maybe 1st into 2nd. If I happen to come to a stop before it has a chance to shift, then when I accelerate from the stop, it'll feel like I'm starting in 2nd gear. This only happens for the first minute or two of my trip then all is fine until I park for a bit and go again.

I had a transmission place have a look a while back and they described a part that, as best as I can explain, regulates when the transmission shifts. I may be simplifying the diagnosis, but that's off memory.

What am I looking at here? Is this a simple fix? A common issue?

Appreciate the advice...I'm trying to sell it and I don't want any issues to hold me back.
 
I will definitely try that but if doing a reset is only a temp fix, what is the true fix? What’s the real culprit?

Appreciate the help!
 
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@julietpapa The occasional hard shift from 1st to 2nd when cold is without question your pcm. Rough idle and shaking mirrors are also two symptoms that will not throw a CEL.

Other known symptoms are: Hugh transmission temperatures, o2 sensors showing bad when good and 1600 codes.

Weather does play a part in the pcm’s performance as well. The hotter it gets outside, the more pcms start failing.

You can call me to discuss in further detail and I apologize for the delay in responding.

Thanks,

Mark Cantrell
 
Well, I've been telling my wife for months that I should order a PCM from Wranglerfix, this morning she finally agreed. My '06 Rubi LJ was running just fine, but I knew it was only a matter of time before it failed. The wife was driving yesterday and between the hard 1/2 shift and rough idle she saw the light. PCM on the way!
 
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