I need some help in understanding the operation of my Grand-Am's 3 speed transaxles TCC. At first I thought I smoked the trans because shifting into any gear the car would die as a feeling of the trans been 'locked'. I assumed there was no TCC in these as there's no OD, but looking under the hood I found a connector exactly like the 700r4's and disconnected it. Now it operates fine, but now i'm confused because:

In 700r4's theres a pressure switch to only allow lockup in high gear, and also a brake switch to override lockup. It failed during a stop, so I figure there's no provision and don't understand the lockup wiring under the side cover. Is there a pressure switch and a solinoid? If so which was more likely to fail, or should I just change both. And also whats involved in this, are these readily accessable under the cover or is there further digging into the valve body to get to these components. I looks as if I need to remove the drivers side motor mount to get the pan off so I need to get in and out to get this ride on the road and really don't need a surprise. Also, as for the gasket, since there's two (at first I figured the stuff was under the bottom pan, but just a filter.... What would the name of the gasket be called?

Any input from the pro's would be greatly appc'd.... Thanks.

 

I'm not a pro, but my friend's '90 Sunbird had the same problem, and he had it fixed at a shop. I was the converter lock up silenoid. It may only be a 3 speed, but it does have the TCC.

 

This is a real common problem on the 125C. Replace the L/U Solenoid on the VB which is under the saide cover of the tranny.

 

Thanks a million. Everyone I talked to says just to leave it disconnected, but I rather have it fixed right. Thanks again.