Ford Fiesta Powershift - rolling back on an incline?

batman2000

We bought a Ford Fiesta 1.0 Ecoboost 2014, powershift (auto) transmission, a couple of weeks ago and I'm still getting used to it.

My issue is this: crawling uphill in 'drive' (doesn't have to be a steep hill) I obviously move my foot to the brake if I need to come to a complete stop. If I depress the brake pedal just enough to stop the car, it stops, but immediately rolls back with my foot still resting on the brake. Stopping the car by pushing harder on the brake pedal prevents it rolling back but causes the car to 'lurch' to a halt. So it becomes quite an uncomfortable ride in stop/start traffic.

Is it just a matter of technique, something I can adjust to? Or is it a problem with the car? Maybe something to do with the 'Hill Start Assist'?

I've driven automatics for the past 16 years and never had this happen before!

AdrianC

Modulate the pedal pressure to bring the car to a smooth halt, then increase the pressure to hold it. Just like you would with a manual gearbox.

This is just another case of how understanding how something works helps you to use it better. The powershift transmission isn't an "automatic", in the old sense of the word. It's a manual gearbox, with a computer doing the changing for you. To be strictly accurate, it's two manual gearboxes strapped together, with one in neutral all the time - they alternate, so that the changes are quicker. Box A does 1-3-5, box B does 2-4-6. When you're in 2, A is in neutral. When the computer thinks you're about to change up, A goes into 3, ready for the clutch to engage as the other clutch disengages 2. When you're stopped, they're both in neutral. "Proper" automatics won't roll back. Manuals in neutral will. You're driving a manual.

batman2000

Thanks... I've been reading around about the powershift transmission, and although I can't pretend to understand completely your explanation does help. It feels very different to previous cars I've driven.

I have been trying to modulate the pedal pressure. We have a slope next to our house and I've been up and down that many times trying to get the knack of it! But it just seems to be all or nothing. Pressing slowly but firmly on the brake brings the car to standstill but not without rolling back a bit. Depressing the pedal more quickly causes it to lurch.

Sigh. More practice is needed! The dealership never mentioned any of this.

AdrianC

If you want to do some looking up on how it works, VW's DSG was the first - so a lot of the basic explanations are around those.

Some nutter even built one out of Meccano...
https://www.selmec.org.uk/article_0004_computer_controlled_dsg_transmission.aspx

batman2000

Thanks again

I'm a bit alarmed at the number of complaints I'm finding about the powershift transmission. It was sold to us as 'automatic'! :-/

takman

batman2000 wrote: »

Thanks again

I'm a bit alarmed at the number of complaints I'm finding about the powershift transmission. It was sold to us as 'automatic'! :-/

It is automatic because you don't have to change gear!. It's just that that it doesn't use the old Torque Converter.

AdrianC

batman2000 wrote: »

It was sold to us as 'automatic'! :-/

Do you have to change gear yourself? No.
How many pedals does it have? Two.
So it's an automatic... If you have an automatic-only driving licence, the definition that matters is how many pedals there are.

But is it, technically, a hydraulic planetary-gear transmission with a torque converter? That, after all, is what we tend to think of when we say "automatic gearbox". No, it isn't. They're dying rapidly, especially in smaller cars, because they're relatively inefficient - higher CO2, higher fuel costs, poorer performance.

Automated manuals, of a range of different types, have been taking over from them for a decade or two now.

iolanthe07

They're dying rapidly, especially in smaller cars, because they're relatively inefficient - higher CO2, higher fuel costs, poorer performance.

But a hell of a lot more reliable and, generally, tried, tested and trouble free.

batman2000

Ok, so technically the car is an automatic, but it drives quite differently to any other automatic I've had (this will be the 4th). The gear change is somewhat jerky, especially from standing still, and the 'rolling back' issue is not something I've had to contend with before. Or at least it was never so noticeable.

takman

batman2000 wrote: »

Ok, so technically the car is an automatic, but it drives quite differently to any other automatic I've had (this will be the 4th). The gear change is somewhat jerky, especially from standing still, and the 'rolling back' issue is not something I've had to contend with before. Or at least it was never so noticeable.

It's not just technically an automatic, it 100% an automatic car because it changes gear by itself.


It just has a different method of changing gear than what you are used to.


When you want to stop you just need to slightly press the brake pedal to slow down then slowly increase the force on the pedal as you slow down then it won't roll back.
What you are doing currently is not pressing the pedal enough to hold the car on a hill and then when it starts to roll back you react by quickly pressing the pedal hard which causes it to suddenly "jerk" and stop.

AdrianC

batman2000 wrote: »

Ok, so technically the car is an automatic, but it drives quite differently to any other automatic I've had (this will be the 4th). The gear change is somewhat jerky, especially from standing still, and the 'rolling back' issue is not something I've had to contend with before. Or at least it was never so noticeable.

Try easing off the throttle gently while it changes - just like you would in a manual...