Engine/Transmission (1994 - 1998) T/C Lock-Unlock

[24valver]

In overdrive my T/C will be locked; then without changing throttle position or grade, the T/C will unlock. It will go back and forth a few times and then be ok for a few miles. It also does it in 3rd with O/D off. Would this be an eletrical problem (TPS) or the signs of my T/C going bad?

P. S- I can slip the converter when its locked up.

 

[fortunate1]

It's called the "overdrive ghost", and has been discussed a bit on TDR forums - though not for a while, I think. Mine has done it only a few times in well over 300K miles. About a month ago while on the highway, it tried to do it again - the O/D off light came on but the trans stayed in O/D locked. This was because I had the mystery switch (keep TCC locked) on. I do think that it's an electrical glitch. BTW, still have my original TPS. Do a search on the ghost in past TDR forums. You may see your symptoms there.

 

[Howard Durand]

I have had a few occasions of the "overdrive ghost" problem but it always resulted in OD being locked out. Had to push the button to re-lock it.

I attribute that to being a PCM problem. .



I have never had a situation where the TC unlocked and re-locked for no apparent reason.

I doubt that the TC is failing, it sounds more liike an electrical or PCM problem. I would suspect the TPS is getting flaky.

Do a search on TPS and you will find a world of different ideas.



There is also the possibility of a loose connection where the TC control plugs into the transmission or where the wire is connected to the PCM.