TCC lockup problems (something different)

[Brian Harper]

I recently had my TCC lockup solenoid replaced because it was locking up all the time and was failing the brake test (lightly touching the brakes at highway speed). Now, the converter is locking up as soon as the tranny shifts into 2nd ! (not a misprint!) If I accelerate slowly from a standstill, the transmission shifts into 2nd normally, then the TCC locks up right away, bogging the car down. If I lightly touch the brake pedal, the converter unlocks and the car behaves normally again. It also stays locked up when I coast down to a stop until either the tranny shifts down to 1st or I touch the brakes.
I can't figure this out at all. The TCC should not lock up until third gear. I haven't crawled under the car to look at the connector yet, but I'm looking at a wiring diagram to try and figure this thing out. Could it be the switches telling the ECM when you are in 3rd or 4th gear maybe hung up? Does the ECM supply the 12VDC to the TCC solenoid the lock it up and, if so, can I check this with a voltmeter at the ALDL?
I adjusted the TV cable and the shift points are good now, but this TCC really has me stumped. Any help would be really appreciated.

 

[WE4]

Bad 3 or 4 gear switch. Grounded wire under pan. Pinched wire to ground under pan. Or Solenoid you bought has a restriction and will not exhaust tcc oil. Did you put a 700 or replacement 200 solenoid in it? I bet you put a 200 one back in. If so, replace with a 700 one and your problem will go away.

 

[Brian Harper]

Thanks for your help Bruce.
You are correct, I did have the shop install one for a 200 R (that was before I read your posting a little while ago recommending the 700r solenoid).
Now some dumb questions:
Can I check the 3rd and 4th gear pressure switches for continuity with an ohm meter?
Is the 200R solenoid really that bad, or can I live with it for a while?
If everything works ok when I touch the brakes (ie. electrically disable the soleniod), can I rule out fluid restriction on TCC exhaust oil?

Thanks again.

 

[Granny 2]

Brian, I went through the same thing last year. I checked all the switches and checked for a pinched wire and found nothing. I checked the wiring all the way back to the ECM and found nothing. I ended up splicing a switch into the TCC wire and turn on the TCC when I want it. Fore some reason it seems like the ECM is telling it to lock up all the time. I tried 3 other chips with the same result. I made a switch pod to fit in the ashtray to turn it on or off.

Good Luck