Torque Converter Lock-up Switch?

There is no switch per say. The computer controls the converter lock up based on rpms, load, ect. Then, it grounds a certain wire leading to the tranny to lock the converter up. In my experience, even with that wire grounded, the converter won't actaully lock up unless you are moving at least 40mph because of a mechanical/hydralic lock out inside the transmission.
So I'd say no, this switch isn't the problem. I did have a torque converter lock up on me once... but that was with nearly 3x the power and torque output of a base 2.3.
You might learn something by jacking up the back tires, and putting it in gear. I would suspect a sensor on the engine to be the cause though.

NicD said:

So when the computer sends the signal to lock up the converter to increase efficiency, what mechanism is it sending it to - some sort of relay or "switch"?

It makes sense that the computer and mechanism would engage around 40 mph, because the car acts as if it were a 5 speed being started in 4th gear...

Maybe the mechanism being sent the signal to lock the converter isn't getting the message to disengage?

Click to expand...

The computer activates a solenoid. I beleive the solenoid cuts off fluid flow to a certain part of the converter, which forces it to lock up. I think you should verify that the torque converter is locked up, by doing some sort of test to see if it is locked. You could even put it in drive, let it die and then try turning the crank by hand.