TCC not locking up

[pure_boost]

Hey everyone. Went to the track for the first time last Thursday for test and tune. Pulled a best of 13.18 @103mph w/ a 2.0 60-ft. on 255/60 radials. Anyway, the next few days i think i remember noticing that the car was running a couple hundred rpm's higher in OD than it normally did at the same speed. I didn't really pay too much attention to it at that time. Yesterday, on the way home from work, i noticed that the torque converter wasn't locking up at all. The fluid level was full when i got home. So i spent today reading through the archives and gnttype. I'm gonna check the resistance through the solenoid and make sure i only have 12v on one wire on the connector over the weekend. I'm also going to hook up a temporary switch that is "supposed" to lock up the torque converter. I don't think it'll do any good, but it's quick and shouldn't hurt anything.

Is there anything else i can check out? Please teach me.

Thanks in advance.

 

[WE4]

Let us know of your results...


Bruce
WE4
www.ptsnctb.com

 

[Geerrhead]

Hi Dan,

Your on the right track. The most likely culprit is the TCC solenoid. It's also possible your brake switch is faulty.

 

[pure_boost]

thanks for the replies.

I just checked things out. Found out a few things. The good news is that I have 23.8ohms btw. A and D on the wire connector for the tranny. Bad news is that I have 12volts to three terminals w/ the key on, engine off, car in park. Any thoughts on where to go from here?

ps. I didn't install the lock-up switch yet. Figured one problem at a time.

Thanks.

 

[pure_boost]

a little more info.

Well, did a continuity test btw. the prongs on the wire connector (not the plug on the tranny) w/ the key off, car in park to see if the wires w/ 12v were shorted together. The meter showed like a 1000mv btw the prongs, which i'm not positive what that means. But at least there is not a definite short btw. any of the wires.

 

[TurboJim]

Check the whole circuit in one shot. With the key on or engine idling you should have 12v to term F in the ALDL. This will ensure you have a complete circuit from the fuse. The ECM grounds that wire (term F) to apply TCC. If you have 12v, and grounding that term WONT engage TCC, then the solenoid might be bad or the hydraulic circuit has a problem. Or the converter is bad of course.

 

[pure_boost]

Thanks for the reply Jim. Where's the fuse at? I looked at the fuse panel under the dash and didn't see any slots labeled "TCC". Maybe I just overlooked it. At any rate, I checked all the fuses and none were burnt out. Anyone have any ideas why I have 12v to 3 prongs instead of just "A"? Thanks.

 

[TurboJim]

Originally posted by pure_boost
Thanks for the reply Jim. Where's the fuse at? I looked at the fuse panel under the dash and didn't see any slots labeled "TCC". Maybe I just overlooked it. At any rate, I checked all the fuses and none were burnt out. Anyone have any ideas why I have 12v to 3 prongs instead of just "A"? Thanks.

I can guess. The third/fourth switches are "open" when they should be closed sitting there. And the TCC solenoid is "open"

Theoretically, by the diagram, key on ongine off or runing, you'd want 12v at 2 pins. The sense wires for the switches (normally closed) wouldt have 12v as theyd be grounded. The TCC solenoid, (with the ECM and/or a switch not trying to force TCC) should be passing 12v so you'd have 12v on the wire coming from the ECM/SOL fuse AND 12v going up to the dash (to ALDL) . 12v on 3 makes me think you have an open pressure switch in there and the TCC solenoid is probably OK. Or you have 2 bad switches and the TCC solenoid is open. It depends what wires have 12v

 

[pure_boost]

Thanks for guessing, Jim.

Originally posted by TurboJim


I can guess. The third/fourth switches are "open" when they should be closed sitting there. And the TCC solenoid is "open"

Theoretically, by the diagram, key on ongine off or runing, you'd want 12v at 2 pins. The sense wires for the switches (normally closed) wouldt have 12v as theyd be grounded. The TCC solenoid, (with the ECM and/or a switch not trying to force TCC) should be passing 12v so you'd have 12v on the wire coming from the ECM/SOL fuse AND 12v going up to the dash (to ALDL) . 12v on 3 makes me think you have an open pressure switch in there and the TCC solenoid is probably OK. Or you have 2 bad switches and the TCC solenoid is open. It depends what wires have 12v

If I remember correctly, pin C was the only one w/out 12v.

My pap found a diagnosing chart in a service manual and we started to go through it last night. So far everything checked out as far as the brake switch working, so one more thing checked off the list.

Ohhh, I think I'm an idiot (nothing new ) I just reread the quote and I probably had 12v on three wires b/c I had the wires unplugged from the tranny when testing for 12v, which probably would've acted like an open pressure switch. (Aside from this being on the internet, don't tell anyone. ) I'll have to recheck that later tonight.

 

[pure_boost]

update....

Ok, I know my thrasher 92 used to lock the torque converter up, so I threw it in real quick for piece of mind on that, but it didn't help. Then I tried grounding terminal F on the ALDL and it didn't lock it up either. I checked the wire connections w/ a test light before road testing that last time so I know I had good connections. Voltage on wires are still on the list of things to be checked again (later tonight). Thanks for all the help.

Later that night......
With the thrasher in, I checked the wires on the tranny again. Didn't have any juice to any of the wires w/ them connected to the tranny, so I pulled the connector off and checked them and had 12v only to "A". I put it back on and checked it again, the juice was not there. With the ignition still on, engine off, i checked pin F and it didn't have any juice either now. Started the car and rechecked, nothing. Wiggled the brake peddle, nothing. Back to the garage again.....

Even later that night......
Ok, I was using the old test light earlier. I don't know why, but I checked it on the battery to make sure it was working well, and it didn't want to light up all the time. I don't think the bulb was making good contact in the socket or something. Anyway, I got out my multimeter and this is what I found w/ the T-92 in, key on, engine off......
1.) 12v to pin F, hit the brake and the power goes off, let off brake and 12v again.
2.) w/ wires connected to tranny....12v to ONLY terminals "A" and "D".
Is this how things should be? If so, I'm guessing the clutch bands in the torque converter are fried. Any other guesses? Thanks.

 

[pure_boost]

Just looking for a little reassurance that I'm on the right track per my last post. Thanks again for giving me some good info on this and basically helping me sort my thoughts out at the same time. I guess I just don't want to have to get a new converter yet, b/c i've always thought that if i'm spending money i might as well upgrade. And a new converter isn't the best bang for the buck upgrade .

 

[TurboJim]

Re: update....

Originally posted by pure_boost

Later that night......
With the thrasher in, I checked the wires on the tranny again. Didn't have any juice to any of the wires w/ them connected to the tranny, so I pulled the connector off and checked them and had 12v only to "A". I put it back on and checked it again, the juice was not there. With the ignition still on, engine off, i checked pin F and it didn't have any juice either now. Started the car and rechecked, nothing. Wiggled the brake peddle, nothing. Back to the garage again.....

Even later that night......
Ok, I was using the old test light earlier. I don't know why, but I checked it on the battery to make sure it was working well, and it didn't want to light up all the time. I don't think the bulb was making good contact in the socket or something. Anyway, I got out my multimeter and this is what I found w/ the T-92 in, key on, engine off......
1.) 12v to pin F, hit the brake and the power goes off, let off brake and 12v again.
2.) w/ wires connected to tranny....12v to ONLY terminals "A" and "D".
Is this how things should be? If so, I'm guessing the clutch bands in the torque converter are fried. Any other guesses? Thanks.

OK, with that info we know the electrical 1/2 of the circuit is GOOD. You either have a bad TCC solenoid, a bad converter or a problem in the front pump (I doubt).

 

[pure_boost]

Thanks for the final reply, Jim. Sorry I didn't check this in awhile, but I changed email addresses and completely forgot that I wouldn't get notified about new posts. Anyhow, wouldn't the 23.8ohms be a fairly good sign that the TCC solenoid was good? I hope so b/c I have 9"A/C NL on the way, along w/ a hardened stator to replace my worn-out stocker.
Thanks again to everyone for the help on this.