XJ won't shift.... any sugestions??

A while back I started to have problems with the trans not wanting to shift in my 89 auto. I did a lot of looking around on here n other sites. What most people said was unplug the TCU and if you can shift manually then the TCU is the problem. Well I've had it unpluged since then due to the fact that I was fixing a lot of other problems. I picked up a TCU yesterday pluged it in and it still doesn't want to shift..... does anyone have any ideas as to what it could be??

If it manually shifts, a problem may be the fuse for the TCU. One is wired in the harness under/behind the glove box. If/why the fuse blew may be another problem.

motoxpete said:

A while back I started to have problems with the trans not wanting to shift in my 89 auto. I did a lot of looking around on here n other sites. What most people said was unplug the TCU and if you can shift manually then the TCU is the problem. Well I've had it unpluged since then due to the fact that I was fixing a lot of other problems. I picked up a TCU yesterday pluged it in and it still doesn't want to shift..... does anyone have any ideas as to what it could be??

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Just to be clear, it shifted Ok w/o the TCU plugged in? If so, then as 8Mud posted check the fuse, if its not the fuse then check the wiring.

yes it will shift if the TCU is unpluged and you shift it manually

motoxpete said:

yes it will shift if the TCU is unpluged and you shift it manually

Click to expand...

Thanks, just wanted to make sure. :cheers:

Then it is either.. fuse, wiring, or the "new" TCU is not functioning also.

If it's a blow fuse, it will act like the TCU is disconnected and it will try starting in 4th gear with the shifter in (D). An 89 will have a fuse in the wiring harness near the TCU itself. The TCU is very rarely the problem.

If it's starting in 1st and not upshifting, then I'd check the throttle position sensor (TPS) as it can also cause no-shifting. A less likely possibility for no upshifting is a bad output speed sensor which would cause it to think you're not moving at all. Damaged wiring is also a possibility. You might have a look at http://www.transonline.com/transdigest/magazines/1997-10/Shift%20Pointers/index.html for some advice on checking things with a meter.

Thank you very much guys, I'm gonna start with a new TPS and go from there. They retail at 59 bucks so my cost shouldn't be to bad. Even if that's not the problem I'm sure it won't hurt, most likely the first one in it's 145000 miles lol

I had a similar problem in a 98. My Jeep would crank up and drive but it would not shift out of first gear. The engine ran a little strange too. My TPS ended up being the cause. It's a cheap part and easy to replace.

You could also test it. Check this link for instructions on how to do it.

http://autorepair.about.com/library/faqs/bl232i.htm

Good luck