Downshifting by itself

[Madcowranch]

WTF? Any time I let off accelerator now and coast, truck starts to aggresively shift down through the gears. Sure scrubs off the speed quick!

No tow/haul or off-road mode activated.

 

[debate]

What's the mph when you lift off the throttle?

 

[Madcowranch]

Seems any speed. First time I let off doing about 80 then tried it at slower speeds with same result.

 

[swoop1156]

Wild. Do you have a tune?

 

[Madcowranch]

No tune. Made an appointment at dealer for Monday.

 

[pirate air]

HAH! That's what you get for sticking up for Toyota!!! lol

Strange, is the check engine light on? Wonder if the electro valve body thinks its in tow/haul all the time. Bet FMS06 might know.

 

[Madcowranch]

HAH! That's what you get for sticking up for Toyota!!! lol

Strange, is the check engine light on? Wonder if the electro valve body thinks its in tow/haul all the time. Bet FMS06 might know.

Ha! I knew someone was going to say it. I'll bet this wouldn't happen on a Tundra!!!

I just took it back out for a 20 minute drive and it's not doing it so IDK.

Man, I don't need trans. problems- my Chevy 3/4 ton is starting to slip. On a side note has anyone put that Lucas trans treatment in anything? I bought a bottle for the Chebby.

 

[BIRDMAN]

Ha! I knew someone was going to say it. I'll bet this wouldn't happen on a Tundra!!!

I just took it back out for a 20 minute drive and it's not doing it so IDK.

Man, I don't need trans. problems- my Chevy 3/4 ton is starting to slip. On a side note has anyone put that Lucas trans treatment in anything? I bought a bottle for the Chebby.

supposedly the lucas trans additive does work to get a little extra life out of a crap trans

 

[pirate air]

Maybe some codes are still in history for the tech at the dealer to review. I bet it's nothing major. I can't remember any completely failed 6r80's come in our shop. They seem to be holding up well-so far.


If the chebby trans is slipping, I doubt the lucas will help or hurt anything. Once the clutches smoke, the only thing you can do is rebuild it.

 

[jdowens1]

5.4 or 6.2 when you let off the throttle does it mildly slow you down or does it agressively slow you down? Brake drag can be issue on 10 f-150 due to stop lamp switch adjustment. If anything I'm thinking it will lead to possible PCM/TCM update adaptive shift strategy clear and relearn.