Manual TCC lockup. OK to leave TCC locked between 3-4shift? | Ford Explorer Forums - Serious Explorations

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Manual TCC lockup. OK to leave TCC locked between 3-4shift?


Active Member
November 2, 2009
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Year, Model & Trim Level
91 XLT
I have been trying to chase down why my TCC will not lockup. Its not a tranny problem because the manual switch locks it right up. Since this is basically a 80% off road truck I am done wasting time trying to figure out why ECU will not command TCC lockup, so I installed the manual ground switch. My question is it hard on the tranny to leave the TCC locked between the 3-4 gear shift on normal accel? It doesn’t feel too firm or hard on the tranny, but I just want to be sure. Thanks for the help!!

I too have a TCC lock up problem, thought I had it fixed but problem returned. I have been monitoring the lockup with a volt meter on (ground) computer side of the TCC solenoid and the PCM is commanding lock up, so mine is a trans problem. Anyway in answer to your question, when mine is working the TCC stays locked when the trans shifts from 4-5, mine is a 5 speed. I know this from monitoring. In yours it is 3-4. Hope this helps
As you probably know the computer uses information from engine sensors as well as trans sensors before it will command TCC lockup, so a bad engine sensor can prevent lockup.

Thanks for the info. i couldn't remember if my TC stayed locked between the 3-4 shift when it was working correctly. I have drove it with it manual locked and the shift feels smooth and not hard at all. Makes me thing it should be safe to leave it locked on 3-4 shifts and 4-3 shifts unless something says otherwise.

Mine does unlock on down shifts.