3/4 pressure switches

[zpd307]

what do the 3rd and 4th pressure switches do? i replaced them as recomended when i had to replace the tcc solenoid, with the 700r4 unit. at least they were cheap. just curious.

 

[Mad_Trbo]

what do the 3rd and 4th pressure switches do? i replaced them as recomended when i had to replace the tcc solenoid, with the 700r4 unit. at least they were cheap. just curious.

Don't they have something to do with the lock up, seems as though they are wired in with the lock up solenoid. Just my guess.

 

[chris718]

they tell the ecm what ratio the trans is operating in"hello ecm i am in 3rd gear,hello ecm i am in 4th gear".this data is part of and integrated with decision making information fed to the ecm for decision making and lock up and timing etc strategies.

 

[zpd307]

that makes sense. thanks!