lockup not working

[pxs]

Okay. Tested C10 - Getting almost 12v when the brake is depressed. If it was the resistor pack, it wouldn't have gotten anything. I tested this on my Wifes XJ, almost 12v (11.75v).

This morning, I went on a test drive. The jeep didn't want to shift out of 1 into 2. and then again it hesitated a little from 2-3, fine with 3-od. Only when it's cold, though. It's fine when it heats up.

At this point, I am thinking I'm gunna cut the C14 wire, and connect it to 12v while on the road, and see if it goes into lockup. I am also going to monitor the output of C14 from the TCU, and see if it gives me 12v when it's supposed to.

I'm also wondering how much help a dealership would be. I know the vehicle has the ability for a computer to be plugged in (and probably find exactly what's going on) to the TCU, but, do they even HAVE that equipment anymore? I've read in other threads that dealers have told folks they can't figure it out.

If i can get the thing to lockup, i might just put in a perminant switch. I'd hate to do that, but i can't think of any other way. This is a daily driver, and i've not really been driving it, as the route to work requires highway speeds. I could drive it around town no problem, though.

It's so strange, this is so all of a sudden that the Tranny is acting like this. One day it was fine, the next, it didn't want to shift out of 1, and the Torque converter never locked up again.

Thanks for the help, guys.
-Nick

 

[torfinn]

Shifting from 1-2 is late (high rpm). This only happens with cold engine / tranny. It is very likely that it is the tps sensor. If you hook up a voltmeter between D1 and D2 and verify the voltage as you drive. There might be a bad connection either inside the tps or in the harness, when the engine is cold. The tcu controls shift from 1-2. It does this by the help of trottle input (tps) and speed (internal speed sensor). Or of course the tcu can be malfunctioning.

You should also pull the fuse to the tcu. You can then test drive the vehicle by using the gear stick as a manual stick. Put it in 1-2 and then it should stay in 2 i think. position 3 gives 3rd gear, and drive 4. This is to verify that there isnt any mechanical failure.

Torfinn

 

[langer1]

I think you have a speed sensor issue.
You said the brake switch was infinity when depressed, how about when not depressed it should be like around 0-2 ohms.

I don't think driving without lockup will ruin your oil. It will be just like old cars from the seventies that did not have lockup converter. Besides the tranny has an oil cooler.

Torfinn

After re-reading this post a bad speed sensor thats failing could be the problem.
They get sluggish and don't work at all cold and can't sense speeds over 40mph when warm.

 

[pxs]

i'll jack the back up and test the speed sensor as soon as i can.

Where is it? I looked, and the only possible thing i saw, that was at the rear of the transmission, was a thing with 1 wire coming out of it, just behind the bracket the holds the t-case linkage pivot thingy. If that's it, i think it might just have to stay there
I only found it by looking at my wifes 2wd XJ. Easily accessable on a 2wd.

-Nick

 

[langer1]

i'll jack the back up and test the speed sensor as soon as i can.

Where is it? I looked, and the only possible thing i saw, that was at the rear of the transmission, was a thing with 1 wire coming out of it, just behind the bracket the holds the t-case linkage pivot thingy. If that's it, i think it might just have to stay there
I only found it by looking at my wifes 2wd XJ. Easily accessable on a 2wd.

-Nick

Thats it,

 

[pxs]

The good news is, the sensor tests fine. Backing down the driveway, the continuity meter beeped consistantly. no problem.

So, i've tested the brake switch. The TCU Gets almost 12v when the brake is depressed (so the resister pack is okay). I've verified voltage on all 12v inputs (from the battery, and ignition) The TPS on the engine side tests fine, on the TCU side it appears to give smooth values (no dirty contacts). Speed sensor tests fine, and the Solenoids all had equal values of resistance. The comfort/power switch DOES works still. The only thing left is the grounds (which i've not tested via the TCU socket, I'll do that later today) and the Diagnostic pin.

I'm all out of ideas. I'll try to jump the Solenoid soon, to see if i can force it into lockup. Is there any way that everything is fine with the TCU, but something is screwed up in the tranny? is there something we're not all thinking about!?

-Nick

 

[torfinn]

The good news is, the sensor tests fine. Backing down the driveway, the continuity meter beeped consistantly. no problem.

-Nick

by consistantly do you mean one long beep. It should be like beep, no beep, beep ...

Torfinn

 

[pxs]

Consistant like regular. "Beep, Beep Beep Beep"
Not constant.

 

[langer1]

Consistant like regular. "Beep, Beep Beep Beep"
Not constant.

Have your checked pump pressure? Your getting closer to a bad toqure converter or bad internal seal.

 

[pxs]

Yeah, I know. No i don't have the capabilities to measure the pressure.

i'm gunna try to jump the wire and see if it will lockup. If it does, i know it's electrical, before the transmission. If it doesn't lockup - Bad Torque converter or something = New Tranny.
I'll post results of that test as soon as i do it. But in the meantime, if you guys have anymore ideas, PLEASE let me know.
-Nick

 

[langer1]

The torque converter and the transmission are two separate parts and sold separately.

 

[pxs]

I underand that.. I meant more along the lines of the same work was involved whether i used the old transmission or the new one.

 

[pxs]

Okay guys. I should have done this test first thing. It would have shown my TCU Is fine, and all things associated with it (like the damn brake switch, TPS, etc, etc)

I tapped C14, and connected it to a multimeter. I drove down the road, and when it should have gone into lockup, i got 13.8v. When i let off the gas, it went to 0v. When i hit the brake (foot still on gas) It went to 0v. However, the torque converter never locked up.

Also, again this morning (about 45-50 degrees here) it didn't want to shift out of 1st. I think there is something up with the tranny (versus the torque converter) and remember, the solenoid tested the same resistance as the other two.

So, options:

- Send vehicle to transmission shop, where they'll probably tell me to replace it. But they might be able to fix something??

- Find a nice used transmission/torque converter and do direct swap (i've read all wires are the same, even if i get a newer transmission)

- Swap in an AX15, and associated parts.

- Sell the heep, and start all over again.

I can't find much info on swapping in an AX15. Only found stuff for swapping the AW4 in.. maybe i should stick with the automatic? Tips, suggestions?
-Nick