Chinese EV refuses to stop 4

[Pud]

'I was kidnapped by my runaway electric car' -

https://www.bbc.co.uk/news/uk-scotland-67005620

Politicians like to panic, they need activity. It is their substitute for achievement.

 

[LittleInch]

I suspect what the policeman did was simply put the controls into Neutral and apply the electric handbrake....

It does look like there is a significant electricity regen system on these cars and you then clearly need to press quite along way to get the hydraulic system working. Seized / ineffective hydraulic brakes are an issue in some cars and usage as they can get very little use.

I doubt we will ever get to know what actually happened...



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[LionelHutz]

The complaint about Toyota's software was an inability to detect cosmic-ray flipped bits; the failures demonstrated required decapping the computer and placing wires to create connections that aren't part of the computer.

The Toyota software was pretty shitty, there were some experts involved in the investigation or lawsuit that wrote a fair bit about what they found and it was far from good coding practice.

There were also significant tin whiskers found on the circuit board in at least one pedal assembly.

Still, a lot of the actual complaints sure sounded like the driver also pressed the gas pedal when pressing the brake pedal. Most were of the "as I pressed the brake the car lurched ahead" type of complaint.

No one found any instance of this happening.

That's a rather dumb argument for "it never happened in practice". It's impossible to prove that happened in normal use, since there was no way to detect or record it happening.

If the engine goes wide open throttle not only are you reaching peak power but your vacuum assist on your braking all but disappears as WOT reduces the manifold vacuum.

The booster should hold enough vacuum for at least 2 braking attempts, so yes you've got get on the brakes once and hold them.

 

[enginesrus]

Most all modern cars that have ABS and along with any form of traction control are all essentially a computerized brake system. That system has full authority over any manual inputs, that is how ABS works, to limit and or control fluid pressure to the individual brakes. That is also how back in the day of sudden acceleration, shows like 60 minutes doing a ride along or drive along, the person in real control using something that was essentially a high end scan tool could turn off the brakes, and scared the --- out of the news person driving the car. I find it funny that so many think cars now are just like the old 57 chevy as to how certain systems function.

 

[TugboatEng]

That’s a Bosch system, but I doubt the Chinese use it in those MG’s which are flooding the market.

Where do you think it's manufactured?

 

[hokie66]

Sure, the Bosch system is manufactured in several countries, including China. But I still doubt those cheap MG cars use them. I could be wrong. The Japanese manufacturers are the largest consumer of the Bosch system.

 

[LionelHutz]

That system has full authority over any manual inputs, that is how ABS works, to limit and or control fluid pressure to the individual brakes.

It can over-ride the brakes when it activates. The fluid passes directly through the valve body when it's idle. I can't wait for your next thread about how these systems are complete crap...

 

[human909]

Most all modern cars that have ABS and along with any form of traction control are all essentially a computerized brake system. That system has full authority over any manual inputs, that is how ABS works

Full authority? That is not my understanding nor is it what I'm lead to believe by a brief google search. By inference it has an ability to briefly reduce pressures in the system, it does seem to have the ability to act as an endless reservoir or seal off the connection to the brakes completely. Reading some of the failure modes of faulty ABS would suggest that this is the case.

The brake system is is made as a robust and redundant system. Additional controls on it generally are additions and do not remove the fundamental hydraulic linkage between the actuated pedal and the brakes.

All that said we did have brake by true brake by wire over 2 decades ago

https://en.wikipedia.org/wiki/Sensotronic_Brake_Control

. There are some very good reasons we've stuck with the safety of hyrdraulic-mechanical systems augmented by electronics.

 

[3DDave]

ABS is often augmented with traction control, the combination allowing both releasing the brakes when the operator operates the brake pedal and applying the brakes when the operator is not.

The decision trees for either are likely long enough that failure will tend to disable the function rather than enable when unwanted.

 

[Factoter]

Yesterday heard from a neighbor of unusual brake failure on late model hybrid SUV:
Two new vehicles owned by young family, wiring harnesses of both vehicles chewed by rodents,
Cars are garaged, and home is in semi-rural exurbia California.
Two weeks ago first vehicle is a No Crank, No Start.
Dealer replaces wiring harness, 12k dollars, owner sets traps in garage; catches a mouse.
Release mouse in nearby field.
Two days ago, driving second vehicle, car is running rough, like a misfire
Owner claims brakes failed with kids in the car, in their words:
“There were no brakes. Had to push brake pedal all the way to stop the car.”
Owner has returned vehicle to dealership, and is buying another, because:
“Rodents ate the brakes. It can’t be fixed. It’s not safe.”

I kept my thoughts to myself. But fully sympathetic. More or less.

 

[3DDave]

Some makers used soy-oil based wire insulation that was particularly attractive to rodents. Replacement with OEM parts is futile.