Cherokee89sport

Alright my renix Cherokee isn't shifting right. I can tell when I take off in drive it is defaulting to 4th, and my tq isn't locking up. Therefore I have to rev it quite high to get it to move. However I can manually shift it through 1-2 & 3 and there is no "slippage". I've determined the TCU is getting power. I even verified the right voltage from the TPS. Is there any way to verify the TCU? Or is there anything else i'm missing?

I have tried ground refreshing.

peep

Check out Cruiser54's Mostly Renix Tips, has a lot of tips and section on checking the two connectors near the trans dip stick tube, grey and black connectors, unplug, spray contact cleaner, check for debris or bent pins, reconnect. Also on checking the plug in at the TCU under the dash glovebox. again contact cleaner. Sorry I don't have any test data for the TCU itself. I picked up a spare at the wreckers. Try to get same year as I believe there were changes made in post renix applications.

Cherokee89sport

Trust me, I've already done all of that. Yea I just went to the JY two days ago and its over an hour away. I'd really hate to drive there again. So if there's any test I can do to it to save me the trip, that's what i need.

DFlintstone

peep, you always have good stuff.

Sport, until someone else comes along. Can you tell us your input, and out voltage on the square trans side, of the TPS plug? (mine went bad, with the flat engine side good).

They work opposite. There are two deals in there. (the TPS on an automatic)

cruiser54

How's the inline fuse right next to the tCU that's wrapped in the yellow tape?

Cherokee89sport

The fuse is fine, the TCU is getting power.

And If I remember right, it was 4.8 and 3.98 v at the tps

cruiser54

Not a common failure. Get a used one, preferably out of an 88 or later.

Radi

You could put a test light or similar on the TCU connector, checking each solenoid output to see if it's trying to operate them.

DFlintstone

Hey Chuck, you where right about my jeep genitally pulling to the right, was the tires. Still only have 3-1/2 of the "round kind" but making progress.
I got a nice pair with studs....that don't seem very easy to get out, waiting here...

YES, Sport, the PO of my Jeep needed to change the TCU, and the one I have now has issues as well. (no ground for the trans side of the tps). Seems to work OK like that though. Agreeing with Cruiser, they do go bad.

Radi

I had an odd shaped one last week, lol. Picked up a nail in the tread shoulder. Plugged it to get back home, upon arrival I found an egg growing next to the plug. A couple more miles and I'd have left a chunk of tread behind.
Less than 3K miles on the tire. Someone** cheaped out and didn't get the road hazard either, lol.

DFlintstone

Sort of similar story. I felt it waz bad enough to swap in my spare for a town trip. I swapped the wrong one! Barely made it home with major separation. Hold on, let me take a photo. OK, here in my little octagon is one of the two studded 235's I just got at a yard sale for $30 (the pair). Pulling the studs is not easy. I got 5...just maybe 50 to go! I think the tread is a tad better than the flash shows. A tad.

DFlintstone

Ah..phit! Really? man that truly bites. Dang...3K? I hope you talked to the manager of someone. That ain't right. But then the plug....(I might have done more than 30 of them Btw. Bal-Camp use to sell good ones).

Cherokee89

DFlintstone, pulling the studs are easy if you do it the right way.
Get an long thind bladed screwdriver and insert it at the brim of the stud and slowly work the tip under the bottom of the stud and then wedege it out. It takes about 15 mins to do a typical 160 stud winter tire if they not are glued to the bottom like rally tires.
I usually get studed winter tires that the stud is worn flat and no longer is useful for winter driving, take out studs and voila have perfect tires for off road driving.
Hope you can understand my explaining and my bad english.

Cherokee89sport

Turns out it was the TCU, a used one fixed the problem. FYI, when it went out, it happened gradually, it became harder and harder to take off in drive. I knew it wasn't a mechanical issue because I could take off in 1-2 just fine but not in drive. Just in case anyone has this problem in the future.

cruiser54

Thanks for the update.