No answers as of yet. And it's not for a lack of tring to fix this thing. Maybe I should re phrase the question. Would be nice to determine something before changing the trans. With the transmission fuse pulled I should be able to shift through all the gears manually Correct ? Tested this in my other good truck and have all gears. 1234. Exact same thing 96 / 97 4l60e. However only have 3 and 4, drive and over drive in the problem child. What ever is going on has caused the transmission to turn off all forward gears, and acts like the gears are all neutral. Have to pull fuse, disconnect main trans connector, or force shift with the scanner. Moves in drive and over drive only, no 1 or 2. All electrical parts in trans have been replaced. Throttle position, and speed sensor have been replaced. Ecu has been replaced. Aftermarket alarm system has been removed. So why has this thing shut down the forward gears? Why no 1, and 2 ? Why no transmission codes?

 

I no trans. guy but internal fluid pressures have to be checked. I don't waste time/money on transmissions, I just pull them and take them to the trans. guy for a reman. .
Electronic trans. could have trans. module / programming issues or valve body issues. It's not as simple as the Turbo 400 days.

 

I hear you there, the 400 trans more simple set up. I have rebuilt one before, still have it never has given me any problems. If this were the old days I would pull and have it bench overhauled. Retired and this isn't the good old money making days. Was hoping for a simple fix and have truck on the road. I have three good used transmissions on the shelf. Not for a lack of parts. Just don't want to get into a situation where I swap that trans and have the same issue. I've read hundreds of posts and that seems to be very common. Need to know why this thing is messing up. Then make the best decision. Thanks