O/T: '93 Cavalier, torque converter problem

The car is a '93 Cavalier, 3.1L V6, 3-speed auto with lock-up converter.

Found a 4-wire plug unhooked on the transmission, plugged it in, now torque converter doesn't want to unlock. Called auto parts, got TCC solenoid, doesn't fit. Original part only has bracket and mounting hole on right side. All aftermarket ones have brackets on left and right, so won't fit.

For clarification, this is the solenoid mounted inside the side cover on the transmission, behind the left front wheel. No other transmission solenoids are available, according to the parts store.

There is no OEM number on the original solenoid. How do I determine the correct part number? Surely this can't be a dealer only item?

Suggestions are appreciated.

Thank you,

Anthony

Sounds like your solonoid isn't your issue since it locks when you plug in the connector. If the solonoid were bad, the TCC wouldn't engage when you plug it in. It sounds like there is a hydrolic switch that is stuck. If I'm not mistaken, the TCC isn't supposed to come in untill 3rd or 4th gear. On some models it might be 2nd gear. If I were you I'd check the manual and look at the schematics and see what switches are in the TCC circuit for that model. There is probably a 2-3 or 3-4 switch stuck closed.

That is not correct.

When they go bad they stay locked in.

You can drive them with it unplugged you just wont have lock up and it will not cause any damage.

just call gm you might have to give then your last 8 of your vin number if you go on a long trip it will cause your trany to heat up cause of your torque con is slipping

I hate to point out the fact that he said it's disengaged if it's not plugged in and engaged when it is plugged in. That means his solenoid will engage and disengage the TCC. That is the only two things that solenoid can do, so that component is working properly. The problem has to lie elsewhere, either with a hydrolic switch or the signal from ecm itself. A solonoid that is physically stuck won't drop out when the electrical control is removed.

One important bit of information would be "does the TCC disengage when the brake pedal is depressed?"

When they go bad when you put the vehicle in gear and it will cause the vehicle to buck and/or stall the engine.

They act like when you dump a clutch on a manual transmission vehicle and kill the engine.

If you unplug it the vehicle will operate normally it, just will not go into lockup.

I have had a couple of vehicles do this, sold hundreds of them when I was a parts person and had many installed in my shop when I was a service manager.

If it's intermittently sticking, then yes, disconnecting it will prevent it from never being engaged and prevent the possibility of it being physically stuck in the engaged position. However that condition hasn't been posted. That is why we need more information from Anthony.

If the break pedal drops out the TCC or if it disengages when the plug is disconnected, then I would look at the circuit first to see if the solenoid is being electrically activated when it shouldn't be. I don't doubt they go bad, they are electromechanical components made by humans and subject to failure, however replacing one is a messy job and if you haven't done your basic troubleshooting, you can't be sure a tcc solonoid will resolve your issue.

MSJ is right.

They fail mechanically, not electrically. Very, very common problem on the 3T40 transmission.

The lad has a bad solenoid.

Allan

Thirty years ago when I first got in the electronics business and went to my first company training class, one of the first things the instructor said was "Milk the front panel before you break out a screwdriver". What he meant was find out what does and does not work before you start messing with things so you don't mess with things that aren't broken.

Now as I point out earlier, I agree these do go bad and it could be his issue since there important information that hasn't been reported back. You'll also notice I haven't committed to saying it's not bad either. I've simply offered a simple process to determine beyond a shadow of a doubt what the case really is.

When you can confirm an issue by simply depressing a brake pedal or disconnecting a connector and seeing if the problem goes away or not, then it's very foolish not to go that next step. It can save you a lot of time, money and embarrassment.

I learned a very long time ago that if you commit to something is a certain way before all the information is in, such as "that can't happen", you will be proven wrong almost every time.

Yeah,

But when you've worked on the goofy things day in and day out since they first hit the bricks and you're paid on a commission basis, you either know what's wrong when they pull thru the door or you find another line of work.

So, I'll say it once again:

The solenoid is bad and no amount of depressing the silly brake pedal is gonna change that fact because this is a mechanical failure which won't allow the circuit to exhaust the clutch apply oil pressure.

Here, I'll make it even simpler:

The solenoid plunger is jamming/cocking/locking "sideways" in it's bore when under pressure and it will not retract.

It will work just fine out on the bench and without the pressure. But when installed in the transmission and the 60lbs of line pressure is in the mix, the solenoid will jam and hold the converter locked until the engine is shut off (which looses the constant oil pressure).

The job pays a whole screamin' .8 of an hour from the time it hits the door anyway, so running around with a complete and lengthly model-wide diagnostic tree in yer pocket is a total waste of time.

Now, if the car should come in and it sounds like a diesel...........ooops, thats another whole chapter. :>)

Allan

You guy are easy to mess with. LOL