ATX shifting question

[tery]

Hey, can you tell me what is responsible for telling the ATX to downshift when you give it about 2 inches of gas pedal at say...25mph? I'm thinking that it should be and it doesn't until I give it a lot more and then it seems like it sometimes goes all the way back to first, whereas I expect it to just go to second. Which sensor does that? or is it a function of vaccum??

 

[rubydist]

the pcm decides that, based on a whole set of parameters. the pcm also "learns" how you drive, and if you drive like a grandma it will upshift sooner and downshift later, whereas if you drive it like you stole it the pcm will upshift later and downshift sooner.

what gear is it in at 25 mph in your example? it should be in 2nd (or possibly 3rd), so downshifting to 1st in that example is not "wrong".

 

[tery]

Thank you for that info Fred, and...if you want the pcm to start "learning" all over again from the beginning...will it do that if you disconnect the battery??

 

[Fordlover96]

Thank you for that info Fred, and...if you want the pcm to start "learning" all over again from the beginning...will it do that if you disconnect the battery??

Disconnect the battery cable and leave it overnight. Whenever I had to do that while repairing something else the car always acted like a confused 5 year old for a couple miles before it relearned.

 

[SHOdded]

A fuller description of relearning idle etc:

http://www.shoforum.com/showthread.php?t=10161