Citroen C3 semi-automatic - Left-foot braking - Thersites
On this car (semi-automatic with an automated clutch), if you left-foot brake with the throttle open, there is an almighty thud from the transmission, the engine unwinds to idle (c. 1000 rpm) and refuses to answer the throttle pedal for a good 30 seconds.

The selling garage's service chap said, 'why would you want to brake whilst accelerating?' to which I replied 'to keep the engine alive whilst shaving a little bit off the speed', but they would not accept that. OK, it looks a little odd on the face of it but I always found LF braking faster and safer on my 51-reg Mondeo, plus I really do not appreciate being left without the power to get away from a (hypothetical) 32-tonner standing on his brakes just behind me. Can I reject the car as not fit for purpose on those grounds?
Citroen C3 semi-automatic - Left-foot braking - unthrottled

Seriously?

There may be a few scenarios where simultaneously braking with the engine under full throttle might be useful-you won't find them in normal driving.

Left foor braking is for manoeuvring round car parks-otherwise lerave it to rally drivers.

The engine has an interlock to stop anyone inadvertantly trying to accelerate and brake simultaneously.

Citroen C3 semi-automatic - Left-foot braking - Thersites

Read my post again: I said nothing about full-throttle driving. I am not a rally driver and I don't go in for lunatic hurling around of lethal masses of metal.

The dealer admitted that for the computer to put the car into limp-home mode while it sorts itself out was "less than ideal" (his words). My point is that manufacturers should never have made braking-whilst-accelerating (however gently) into a problem in the first place. My 51 Mondeo didn't have the problem and it was one of the sweetest-handling cars I've ever had.

Citroen C3 semi-automatic - Left-foot braking - coopshere
Definitely not, it's doing what it was intended to do when manufactured, this is something you should have sorted out in the test drive. This is not a semi automatic but as you state an automated clutch system whereas the mondeo was a proper automatic gearbox. Unfortunately for you you have fallen for the marketing hype of several manufacturers who now call their transmissions automatics when in fact they are either dual clutch systems or, as in your case, an automated clutch. Neither of these systems act in the same way as a conventional automatic.
Citroen C3 semi-automatic - Left-foot braking - Fernando P

Left foot braking is something you do when sledging !

Citroen C3 semi-automatic - Left-foot braking - RT

I don't see why you can seriously ask about rejection as "unfit for purpose".

As you're a 1 in a million driver that considers doing this in normal highway driving it's unreasonable to expect the manufacturer to have taken your needs into account.

After the Toyota throttle debacle, I would hope that all manufacturers have modified their controls to cut the throttle if the brake pedal is touched.

There is a place for left-foot braking on loose surfaces - so leave it to rally drivers and farmers !!

Citroen C3 semi-automatic - Left-foot braking - Collos25

Is the OP for real or is this a hoax.

Citroen C3 semi-automatic - Left-foot braking - Thersites

Is the OP for real or is this a hoax.

Not at all: better ask HJ why he advocates left-foot braking...

Citroen C3 semi-automatic - Left-foot braking - colinh

From the Toyota hybrid manual:

"Depress the brake pedal using your right foot. Depressing the brake
pedal using your left foot may delay response in an emergency, resulting
in an accident."

Citroen C3 semi-automatic - Left-foot braking - gordonbennet

Not at all: better ask HJ why he advocates left-foot braking...

HJ might well advocate left foot braking on automatics, but when close manoeuvering, i don't recall him ever waxing lyrical over the benefits of driving down the road with both the throttle and brake pedal depressed simultaneously.

Another difference here being you don't have an automatic gearbox, as some above have tried to explain you bought one of the most vile contraptions ever invented, presumably by satan in a particularly foul mood, you have a manual box with an electronicaly operated clutch and gearchange mechanism, only one of these things ever drives properly and thats fitted by Volvo to their articulated trucks.

Every single automated manual carp car i've driven, nearly all as it happens, cuts the power as soon as you touch the brakes, if they didn't some clown would be standing on the throttle several seconds before lifting off the brakes at the traffic lights for a lightning getaway, more smoke from clutch than tyres.

Edited by gordonbennet on 03/08/2012 at 20:27

Citroen C3 semi-automatic - Left-foot braking - daveyjp
"standing on the throttle several seconds before lifting off the brakes at the traffic lights for a lightning getaway, more smoke from clutch than tyres."

But strangely Audi DSG system allows you to do this! Brakes on, lots of revs, brake off, flying start.
Citroen C3 semi-automatic - Left-foot braking - gordonbennet
But strangely Audi DSG system allows you to do this! Brakes on, lots of revs, brake off, flying start.

I hope the clutch isn't engaged till you lift off the throttle, no wonder these things don't last long.

Amusingly, during my years of driving car transporters, it was sometimes the case that these automated manual cars would either get stuck in the body cut outs or fail to have enough power to pull themselves up onto the top decks, usually needing help in the form of an assistant manually ratchetting the car out of its position, or more precariously by getting a 'run up' part way up the deck, then an assistant raising the deck to head height whilst the driver sat in the car until level enough so the car could pull itself on properly...not for those of a nervous disposition...:-)

You couldn't pay me enough to own one.

Citroen C3 semi-automatic - Left-foot braking - focussed

This old chestnut is common on any Peugeot/Citroen/Renault where the brake is used with the throttle partly or fully open-as sometimes occurs in driving instruction when the car is fitted with dual controls. The pupil refuses to get off the gas pedal when told to and the instructor has to use the brake to control the car ,and the ECU goes into sulk mode. Take it to a dealer who can re-programme the electronics to cope with this.

Citroen C3 semi-automatic - Left-foot braking - unthrottled

I still don't understand why you want to operate the accelerator and the brake simultaneously. It wastes fuel and brake pads! If it's a turbo engine you'll need more than a dab of throttle to keep the turbo on song. It's easier to change your driving habit to suit the car than vice versa.

Citroen C3 semi-automatic - Left-foot braking - skidpan

You are driving a Citroen C3 "automatic", its a slow town car that should be driven as such.

If you want a car to drive using left foot braking etc buy a car designed to be used like but for christs sake don't drive it like that on public roads.

Citroen C3 semi-automatic - Left-foot braking - injection doc

Simples

Fly-by-wire throttle is cut when brakes are applied ! Saftey issue end off !

Do not drive with both feet on pedals ! DANGEROUS ! and its for this reason why manufactures had to put the throttle cut in place !

Left foot braking is for a track not public roads ! DSC if fitted to most cars now so why should you ever want to left foot brake ?

Is this for real or a wind-up !

Citroen C3 semi-automatic - Left-foot braking - SlidingPillar

Only use I know for left foot braking while the throttle is open is the technique to keep the turbo spooled up on an older turbocharged car - say about to overtake. Or in competition.

Not a normal road technique at all, and the sort of thing that modern engine management systems could be expected to dislike as it wears the brakes and transmission.

It's a bit like expecting a road car to be happy with a Scandinavian flick to get round corners...

Left foot braking on a closed throttle is another matter - I think it is this that HJ advocates.

Citroen C3 semi-automatic - Left-foot braking - galileo

The Highway Code still recommends gentle braking while driving slowly to dry out brakes (after passing through standing water due to floods or a ford). Used to be normal for drum brakes but probably not really needed for discs.

Citroen C3 semi-automatic - Left-foot braking - unthrottled

That's a fair point, galileo.

The other example is the 'heel and toe' technique. But, the accelerator pedal is placed far too low down in most pedal set-ups for heel and toe to be practical. This is intentional-to avoid the possibility of unitended acceleration during a scramble for the brakes. I expect the rationale behind Citroen's limp home mode is the same. The ECU assumes the driver did not intend to press the accelerator whilst braking and assumes that there could be a fault with the throttle actuator.

Citroen C3 semi-automatic - Left-foot braking - Thersites

There's only one of you who has taken the real point I was making, and that's slidingpillar on Saturday at 4 p.m., all the rest of you over-reacted and started putting words into my mouth which I did not say myself. Libel, anyone?

I take the points about conflicts between braking and even gentle acceleration, but why on earth put the engine into sulk mode when it happens? That could kill someone, for which there is no excuse, whatever inadvertent mistake the driver has made.

In any case, this is only one of the reasons I'm going to get rid of the horrible little monster I have bought. The passenger door hit my wife in the face, giving her a bruised eye socket, the air conditioning smells to high heaven because the previous owner didn't use the car for weeks on end, the seats give me sciatica, they are the devil to adjust, the mirror vibrates itself away from where I align it, the gearbox...need I go on? Even the key fob gives an interesting insight into the Citroen mindset; when you press the little button, the ignition key springs out like a flickknife. Horrible car. Why didn't I just get the Merc C220 coupe I saw first?

Edited by Thersites on 06/08/2012 at 12:29

Citroen C3 semi-automatic - Left-foot braking - unthrottled

The passenger door hit my wife in the face, giving her a bruised eye socket.

My fist was once punched by someone's nose. Honestly!

What a miserable list of petty cavils. Classic case of buyers' remorse; you bought a car, decide you don't like it and now you're trying to 'prove' that it is unsafe or not fit for purpose so you can get your money back! It's not going to happen.

Citroen C3 semi-automatic - Left-foot braking - thunderbird

Why didn't I just get the Merc C220 coupe I saw first?

So you had the choice of a Merc 220 or a Citroen C3 and chose the Citroen, no wonder you are trying to get a refund on the car.

Does the Merc let you brake and accelerate at the same time?

Feel sorry for any saleman that you contact.

Citroen C3 semi-automatic - Left-foot braking - Avant

Citroen's semi-automatic transmission is about as fit for purpose as your disfavoured namesake Thersites in the Iliad, and needs gentle treatment. It's jerky and unreliable even then. I agree with Slidingpillar about the point of braking and accelerating together, but I think any transmission won't last for long if you do this sort of thing regularly.

If you want a car with lots of acceleration, a semi-automatic C3 should be low down on your lost: indeed if a Mercedes C-class coupe was also on the list, maybe you'll have better luck with your next car if you rationalise exactly what your priorities are for a car within your budget. Performance? Economy? Size? Petrol or diesel? Etc.

Edited by Avant on 06/08/2012 at 23:39

Citroen C3 semi-automatic - Left-foot braking - injection doc

Having had a E250 merc 59 plate I can assure you that feet on two pedals at once is a huge no no. It nearly killed me once on the A14 trying to do a quick 3 point turn.

With a Merc when you go from reverse to drive it can take upto 4 seconds to engage ! & if you touch the barke and accelerator together it confuses the carp out the car !

worst back braking unreliable car I have ever driven. Seat was a killer. Blue efficencey injectors a nightmare ! autoheadlamps that used to dip at the slightest light comming the other way, even if it was an outside lamp of a house !!!!!!!!! electric windows that had a mind of there own and seats that were so uncomfortable that two years later I'm still suffering with my back

Citroen C3 semi-automatic - Left-foot braking - gordonbennet

''With a Merc when you go from reverse to drive it can take upto 4 seconds to engage ! & if you touch the barke and accelerator together it confuses the carp out the car !''

There's progress for you, mine changes from reverse to drive, or t'other way, in a split second, never ever use my left foot, no need, the vehicle is infinitely and instantaneously controllable just by using the right foot, all hydraulics, dreadfully old fashioned doncha know...:-)

Oh and the seats are comfy enough for any distance.

80's design, last of the model regd in '96, not in the least interested in the latest all singing all dancing electronic nightmares, whatever badge is stuck on the boot.

Citroen C3 semi-automatic - Left-foot braking - laworr
Heated though it became, I appreciate this thread. We have a new C4 eHDi. Several times I've been caught - in flat, sedate, town driving - with the engine in what is colourfully called 'sulk' or limp mode here. Once it nearly caused an accident; other times I've worried the car would snap out of the sulk and accelerate violently. The only cure I've found seemed to be to depress the brake fully - and I was attributing the issue to a problem with stop-start system.

I think I better understand the issue as an interactive one. In town driving I unconsciously find myself sometimes balancing the forward motion by little braking in between accelerating. I barely knew I did it - but remember I developed a left foot usage working the ancient clutch on my old DS21, then must have carried that over to the Subaru 1999 wagon we had - especially on hill starts - whose standard automatic transmission could handle left foot braking occasionally overlapping with gentle right foot acceleration.

I think I'll eliminate the stop-start theory by switching off the ECO mode and proving that the problem can be deliberately generated.

But I'm grateful to the posters here for giving this mechanical/electronic illiterate up the language to talk about the problem with a service mechanic, and some reassurance that I'm not imagining the problem or experiencing something irrational or unique to my car.