89 XJ Transmission/shifting problem

[Jesse714]

Did you find a blade fuse that looks like this one http://innovision-group.net/catalog/images/image_product.height.50099.png

Nope thats the kind that would be under the driver side, in the fuse box. This is more like a resistor

 

[Jesse714]

There is a resistor in there for the power/comfort switch that goes between the yellow and blue-yellow wires. It's a 'pull-up resistor' for the switch at the brake pedal. If that's broken, the tcu will not be able to sense when you hit the brake and won't know to unlock the torque converter.

I don't recall the value of this resistor off the top of my head. I can go out and measure mine if it stops raining. I think it's probably around a 3.3 k-ohm resistor which can get a 2-pack of at Radio Shack for $1.

There should be an automotive blade type fuse on the yellow power wire going to pin D16.

That would be awesome man, I'll run out and check, i didn't see a blade type, but i should probably double check.

 

[Jesse714]

There is a resistor in there for the power/comfort switch that goes between the yellow and blue-yellow wires. It's a 'pull-up resistor' for the switch at the brake pedal. If that's broken, the tcu will not be able to sense when you hit the brake and won't know to unlock the torque converter.

I don't recall the value of this resistor off the top of my head. I can go out and measure mine if it stops raining. I think it's probably around a 3.3 k-ohm resistor which can get a 2-pack of at Radio Shack for $1.

There should be an automotive blade type fuse on the yellow power wire going to pin D16.

I went out to look, it took me a while to find it, because it didn't have a fuse in it at all, I was wondering what the plug went to... I had original bought it from my brother with a bad transmission (maybe not not lol)
Would this be the cause?
Thanks so much for your help guys!

 

[NW-ZJ-SCOTT]

BOOKMARKING THIS PAGE...

Jesse714 i am having the SAME issue. Take off and as soon as it hits overdrive it will NOT downshift.

89 XJ aw4

 

[lawsoncl]

I went out to look, it took me a while to find it, because it didn't have a fuse in it at all, I was wondering what the plug went to... I had original bought it from my brother with a bad transmission (maybe not not lol)
Would this be the cause?
Thanks so much for your help guys!

Yes. Without that fuse, the trans computer has no power. A 10-amp fuse should work.

 

[Jesse714]

BOOKMARKING THIS PAGE...

Jesse714 i am having the SAME issue. Take off and as soon as it hits overdrive it will NOT downshift.

89 XJ aw4

Well hopefully these two things will fix your problem, and im guessing that your going to need the resistor ( which i guess tell the TC to unlock) Because your if fuse was blown, im sure it wouldn't take off in OD, just like mine, Im anxious to go and test drive it, but i have a feeling it may not be fixed because i haven't had a chance to get that resistor.

 

[Jesse714]

Yes. Without that fuse, the trans computer has no power. A 10-amp fuse should work.

Well i think that would explain this whole issue.. This is pretty exciting, haha, just because i put so much money into it, when it could have just been those two things, I've been trying to think about the blade fuse, i don't remember ever pulling it out, so i'm thinking my brother pulled it out at some point, without knowing what it did.
I really hope this fixes my problem.

 

[NW-ZJ-SCOTT]

Well hopefully these two things will fix your problem, and im guessing that your going to need the resistor ( which i guess tell the TC to unlock) Because your if fuse was blown, im sure it wouldn't take off in OD, just like mine, Im anxious to go and test drive it, but i have a feeling it may not be fixed because i haven't had a chance to get that resistor.

i'll replace all of it. my rig is down untill june. i have plenty of time to tackle this area :clap:

 

[Jesse714]

Well i can't thank you guys enough. YOU HAVE FIXED MY PROBLEM!!!!
I still have to get that resistor, but the jeep is now drive able in overdrive!
Thanks alot guys!!

 

[Jesse714]

i'll replace all of it. my rig is down untill june. i have plenty of time to tackle this area :clap:

Hopefully it fixes your problem as well, If not, It could be the shift solenoid in the transmission pan (i have all three) or it could be the actually TCM, which i have one of those also.
So if those two don't fix your problem, let me know and we can work out a shipping arrangement.

Happy XJ'ING

 

[lawsoncl]

Well i can't thank you guys enough. YOU HAVE FIXED MY PROBLEM!!!!
I still have to get that resistor, but the jeep is now drive able in overdrive!
Thanks alot guys!!

I measured the resistor on mine at 1.3 kohms. So these would probably work nicely. http://www.radioshack.com/product/index.jsp?productId=2062324.

If they can't find those, you can probably use 2.2 kohm, 1/4 watt resistors. I wouldn't go with the 1/8-watt rating as they are physically smaller and might get a little warm.

 

[NW-ZJ-SCOTT]

Hopefully it fixes your problem as well, If not, It could be the shift solenoid in the transmission pan (i have all three) or it could be the actually TCM, which i have one of those also.
So if those two don't fix your problem, let me know and we can work out a shipping arrangement.

Happy XJ'ING

Well i tore into the dash, found the fuse right away, kind of "taped" to the harness about 2" down from the TCU plug.

Fuse was fine? all the wiring looked good and tight.

where is the resistor you were talking about? my power/comfort switch does not work. i have replaced the switch 3 times.

How much would you want for the shift solenoid(s)? I think i am going to start a process of elimination. Junkyard parts are cheap. i'll grab a TCU, a couple of these "resistors" and i'll do a tranny flush. and i'll replace the solenoid(s?) while im at it. this problem has gotten the best of me, i've ignored it for far to long, its making the jeep extremely annoying to drive.

 

[Jesse714]

Well i tore into the dash, found the fuse right away, kind of "taped" to the harness about 2" down from the TCU plug.

Fuse was fine? all the wiring looked good and tight.

where is the resistor you were talking about? my power/comfort switch does not work. i have replaced the switch 3 times.

How much would you want for the shift solenoid(s)? I think i am going to start a process of elimination. Junkyard parts are cheap. i'll grab a TCU, a couple of these "resistors" and i'll do a tranny flush. and i'll replace the solenoid(s?) while im at it. this problem has gotten the best of me, i've ignored it for far to long, its making the jeep extremely annoying to drive.

I would replace the fuse anyway, Just to try it, The resistor is wrapped in a tough plastic, its hard to see, but it's between yellow and yellow and blue wires. I have another TCU sitting in my jeep, i grabbed one while i was at the junkyard last time, thinking it would fix my problem. I also ignored, i just shifted it manually, and that got really annoying.
The solenoids are 300 or so on shucks, for whatever reason i don't know why they're so damn expensive.
So i'd say 25 +5 bucks for shipping, does that sound fair?
I can't remember which solenoid is which, 2 of them are the same, and then one of them has a different style of mounting bracket, so i'd just replace them all.
2 of them are a goldish color, and 1 of them is a silver/gray.
2 of them are out of my 96 transmission, the other is out of the 89 transmission, i replaced the OD and 1-2 hoping it would fix my problem.
I can get you a picture if you'd like, or you can PM me.

 

[Jesse714]

I measured the resistor on mine at 1.3 kohms. So these would probably work nicely. http://www.radioshack.com/product/index.jsp?productId=2062324.

If they can't find those, you can probably use 2.2 kohm, 1/4 watt resistors. I wouldn't go with the 1/8-watt rating as they are physically smaller and might get a little warm.

Thanks a lot man, I'll either order it or drive down there and see if i can find it.
Thanks again for taking the time to measure it, its kind of a pain to tear your dash apart.
arty:

 

[Jesse714]

Well i tore into the dash, found the fuse right away, kind of "taped" to the harness about 2" down from the TCU plug.

Fuse was fine? all the wiring looked good and tight.

where is the resistor you were talking about? my power/comfort switch does not work. i have replaced the switch 3 times.

How much would you want for the shift solenoid(s)? I think i am going to start a process of elimination. Junkyard parts are cheap. i'll grab a TCU, a couple of these "resistors" and i'll do a tranny flush. and i'll replace the solenoid(s?) while im at it. this problem has gotten the best of me, i've ignored it for far to long, its making the jeep extremely annoying to drive.

There is also a transmission fuse under the driver side dash, i think its 7amps but I'm not to sure, i would try to replace that. These comfort switches are junk, no wonder they got rid of them.