Approx. once a week my transmission will downshift to 1st gear with no warning as I am driving (usually accelerating) at any speed and then pop back to Drive, this has happened 4 times now. A mechanic friend accessed the computer and found the fault code P0957 which means, I'm told, Auto Shift Manual Mode Circuit Low. No one seems to know what the problem is, is it a module, a connection, or a computer programming error? How can I fix this before I blow up my transmission?

ehestdalen

 

this is the sensor that controls manual shifting. this will be a dealer item im sure. normally the pressure sensors go first but i would have to say that random high rev shifts would blow either the more or tranny

 

Welcome to the site. Is this a Cummins diesel?
FF

 

Yes, 6.7, a great engine

eh

 

Try this link to a doc I uploaded for you on that code

http://cid-fb87bd8396fbfbf4.office.l...00%20P0957.pdf

if you need anything else PM me as I dont check this section