Originally Posted by mmcrh
Has anyone experienced or known that gear downshifts and "locked in" on uphill regardless how hard gas pedal is pressed (rpm goes up like crazy) ? The same happens on flat road when hard accelerate for overtaking. This occurred after the dealer applied TSB transmission flash 4 month ago. The flash cant be rolled back. The dealer tried adaptive re-learn to no avail.
Also saw your posts in the other thread about the TSB that was applied.
2014 CRD + 8-speed: MAJOR shift enhancements/improvements 08/27/14
I don't know if I have that update. My vehicle is in the manufacturing date range but I didn't pick it up until end November. I dont have any issues as described in the pre-update symptoms, so maybe it is updated?
Anyway. From what you described here, flooring the accelerator up a hill you would expect the box to change down one or more gears. So I'd say this is normal.
(this 8HP70 is pretty clever it can shift directly
from 8th to 2nd if it has to.)
If you keep your foot mashed up the hill then of course it will rev higher until either the loading eases of, so it changes up a gear or you hit the rev limiter. I'd say that is also normal for the gearbox when pushed like that.
If you did the same to overtake on the M4 the same thing would happen but the load will be less on flat ground and you'd be going very fast (maybe even over the speed limit
) but as the load on the box decreases it will change up a gear.
Are you hitting the Rev limiter and the Gearbox is NOT changing up a gear?
I haven't revved mine that hard so I don't know what it does. I've only hit the limiter in the manual transmission cars i've owned, and maybe the odd hire car.