Torque Convertor Not Staying Locked In

[3quarterdone]

I have a 2000 S10 w/2.2. After TC lock up is made it slips back out and then right back in to lock up, over and over. It does this in 3rd or over drive but only at certain speeds. As soon as I hit 58 MPH in OD the converter stays locked in. The problem is, most roads I drive on are 45-55 MPH and I'm afraid all this slipping in and out will overheat my tranny, not to mention the drop in fuel mileage. The fact that it stays locked at higher speeds tells me that the clutch is working, but maybe getting faulty info from the speed sensor? I think there are 2 separate sensors, a in-speed/out speed and a speed sensor for the odometer? I don't know which for sure drives the TC lock, guessing the in/out speed? It may even be the "lock in" solenoid for the TCC is weak? I'm just guessing. If anyone knows more about this problem, I could use some advise on where to start looking?

[dmbrisket 51]

this is going to sound EXTREMELY strange, but look at your temp, if the moter wont reach a certin temp it wont lockup into od, if the stat is weird, it can be hitten temp, then coolen down to far, causing the transmission to lockup and unlock, sounds weird yes, but i have seen it more then once

[3quarterdone]

I dont think the problem is my T Stat because the TC wont lock at all until my Temp comes up to normal ( Just what it is suposed to do ), then it starts it's in/out dance after she hits about 180-185 Deg. Mine seams to run about 195 all the time. It shifts in/out about every 2 seconds but not in rythum. If I run her up to 58 MPH+ as soon as she is warm she stays locked in. One Time ( and this has never happened again ) I started it up and the Speedo pegged at 100+ MPH before I ever took it out of Park. As soon as I backed up it started working normal and has worked ever since. This gave me the hint that It maybe one of the speed sensors, but I dont think the Odometer sensor controls the TC lockup? Could it be both are going bad. Or maybe The fluid is contaminated? Truck has 90,000 .Fluid changed, probably never, who knows! I bought her used.

[maxwedge]

The tcc engagement is speed dependent on any car, along with throttle/load.

[3quarterdone]

What has me baffled is, it does this in/out dance whether I am at low throttle on flat ground or half throttle up a hill. It doesn't seam to matter where the throttle is, as soon as I hit 58 MPH she stays locked in. I would like to change the fluid and filter to see if that would help, but would want to Fix any sensor, valve or solenoid problems while the pan is off.

[maxwedge]

You really should have a full scan done by a trans tech with a full function trans scanner, he can command lock up and look at engagement and slippage errors to find what the problem is here.

[3quarterdone]

That is what I was trying to avoid, The local tranny shops around here tell you, You need a total rebuild if they spot a drop of fluid on the outside of your tranny, even if it splashed up there from a puddle in their lot. I'm glad the dentist doesn't pull all my teeth and give me new dentures every time I go in to get them cleaned! ouch!

[usa1mac]

I'm having the same problem with my 2000 S10 4X4 with a 4.3 L engine.

It's not the temperature, that reads fine. When I took it in for service, the guy did a full scan and said the command to the TCC was being sent continually and he thought it was the solenoid was faulty. He said replacing this would mean about the same labor as putting a new tranny in. It's got 125K miles on it, so there something to be said for putting a rebuilt one in.

This has led me to ask in another thread about how to disable the TCC.

Any thoughts?

Mark

[maxwedge]

How does he equate what appears to be an electrical problem that commands the the solenoid, which by the way is powered all the time and grounded by the pcm based on inputs from the engine, and car speed/load. The tcc solenoid on that trans is a 2 hour job tops. Again a proper scan can see if the tcc command is being lost causing the symptoms, if so the the problem is not in the trans, if not then the tcc is slipping which would cause it's own code. Remember a slight misfire under load in lock up can feel like a bad tcc.

[3quarterdone]

I wouldn't want to disable mine, I want the gas mileage, but here is some stuff I found on the web that can be done and that may help you.

4L60E – Sonoma Tranny
This should increase the grin factor

BULLETIN NO. 000608

June 21, 2000


ANNOUNCING THE AVAILABILITY OF THE FOLLOWING BRYCO PRODUCTS:

FORD, GM LOCK UP ADJUSTER

FOR NEGATIVE SWITCHED TRANSMISSIONS
BRYCO #: 99029
APPLICATION: Lock Up Adjuster for Ford, GM
Negative Switched Transmissions
INDUSTRY #: K77986

FORD

GM
E40D
4L60E
AODE
4L80E
AXODE
4T40E
AX4S
4T60E
AX4N
4T80E

THE LOCK UP ADJUSTER FUNCTIONS BY ALTERING THE COMPUTER STRATEGY
THAT CONTROLS THE LOCK UP AND YIELDS THE FOLLOWING ADVANTAGES:

·

Cures shudder problems caused by slow application

·

Reduces clutch slip

·

Helps to delay lock up under heavy acceleration

·

Simple to install

·

Easy to adjust

PLEASE CONTACT YOUR AUTHORIZED BRYCO DEALER FOR PRICING AND AVAILABILITY.

000608

The 700R4 uses a lockup converter. I love my lockup. The person I spoke to at Art Carr doesn't recommend using a lockup converter, I guess that's why I bought a TCI 3000 rpm stall lockup converter. The lockup converter allows me to have a high stall and cruise on the highway. With 3.73 rear gear and a 28" tire 2500 rpm is about 80 m.p.h.. If I didn't have a lockup converter I would be constantly slipping with my converter on the highway. I don't use the lockup in any other gear than overdrive and I disengage the lockup under full throttle. It's great you can have your cake and eat it too, high stall for good launch, lock up the converter on the highway and cruise home.


Go to SmokemUP.com for the wiring diagram.
I control the lockup on the converter manually. The wiring diagram shown is how I wired my car. I got the toggle switch from the junk yard out of an older Nissan Maxima, it's lighted and says O/D on it. It's simple I push the switch and the tranny locks the converter. In a braking situation the brake switch disengages the converter for me. Sometimes I forget the converter is locked up and I'll bog the motor...ooooops press the button to disengage the converter. I've never used one of the kits for controlling the lockup but I'm the type who likes to control when I want the converter to lock. I hate it when a tranny keeps going in and out of lockup. If this is not for you all of the major tranny companies offer a lockup kit for the 700R4, B&M, TCI, Art Carr, etc.

[troy1]

Does anyone have a p1870 code? The TCC valve in the Valve body wears out. Transgo has a repalcement but it requires pulling the VB. Also check the VSS or TPS for faulty info

[3quarterdone]

My service/check light has not come on so I dont know if it would show any code, maybe the light doesn't work! I'll probably take it and have it checked out. I will let you know what I find.