Buddy has an 01 silverado, been babied its whole life, 144k highway miles, 2wd.
he said that on his way to work it just lost 3rd and od with no warning. I figured sprag or something, so I sold him an extra 4l60e I had laying around that had about 3000 miles on it. Perfect condition.

He put it in and it does the same thing, and it won't go into reverse sometimes. If you turn off the truck, start it back up, and put it in reverse its like everything is fine and goes right into gear, every time.

I plugged in my HP tuners and had to put a fuse in for the diag port, it was blown. Took it down the road and manually put it in 3rd or 4th with scanner, locked converter, still nothing.

It will intermittently have ther gears working fine, and then just slip.

I'm wondering one or two things..Computer is on the fritz, hence blown fuse, or the selector on the side of trans has a problem, since he used the same on on both trans'

I'd really like to figure this out, I want to buy the truck


anyone had this phantom problem before? I've broke a few that acted the same way, but they NEVER had 3rd or 4th after the failure. Ths one acts like it has it sometimes

 

Does it neutral when going into 3 or 4? Does the pcm command 3 and 4?

 

yea it neutral's

I don't know if its commanding 3 or 4 or not. I know I pushed 3 on my hp tuners scanner, which is how I lock a a4 car in 3rd on the dyno, and it wouldnt work

 

Could be a bad selector switch on the side of the tranny.

 

I was thinking that, but never heard of one going out

 

The selector switch should be just for the dash indicator AFAIK, when i had my truck i drove for a while without one when mine got smashed to pieces and it was fine.

 

edit


It was the PCM