Hey, I need to know what all can make it not lock up. Here is the deal. My torque converter all of a sudden stopped locking up. We tested the signal from the brake switch with a test light and it shows power normally and not when pedal is pushed. This should be normal I believe. Anyway, we looked farther through the wiring diagram and can see that the signal goes through the transmission and then up to the computer. The computer creates a ground when it wants to lock up the converter. So we took a self powered test light that shows when there is either power or ground. We hooked it on the wire for the torque converter lock up at the computer and took it for a test drive. It lit red normally which is a positive signal and went out when I hit the brake. That appears so far so good. That means the signal is getting through the tranny and to the computer. Well when I reach lock up speeds it turned green which should indicate a ground which is how the computer locks up the converter. So far so good right?

We also had it hooked up to a snap on scan tool and it showed that the computer is calling for lock up but it isnt happening. From all of this we concluded that it was probably the tcc clutch selenoid. WRONG. I just got done changing it. It was a pain but nothing to difficult. I had to drop the exhaust to get to it because of my duals but got it done.

Ok, next I talked to my cousin which has worked in a tranny shop before. He told me that it was probably the pressure switch in the tranny. He said that he had a good one I can have. Does this sound like the problem. I can't find any thing else it could be. Oh, this sucks by the way because I am running synthetic and any fluid I loose costs me 5 bucks a quart. I just did a fluid change today while I did this but dont want to spend 30 more dollars on it again tomorrow so I am going to try to save as much as possible but without a drain plug that is tough.

Well, I am planning on making leaving to go on a 2-3 hour trip tomorrow around noon. I really want to take this car so I can show it to the person I am going to see instead of my beater. We are going to try to change out that pressure switch tomorrow morning(or today rather in about 3 hours). I just need to know if there is anything I am missing that could be causing this to not lock up. The sooner the better.

Thanks

Ben

 

Check for continuity at the tranny connector between the power wire and the grounding wire terminals (I don't recall which is which). It should be the resistance of the solenoid. If it is open, the switch is bad, or you have some other break in the circuit.

I'm not sure you have actually verified you have power at the tranny with what you've done. I was seeing power down there, so I figured I did - turns out I was actually checking the 4th gear circuit. When I got power down to the right circuit, bingo, TC started locking.