Man killed because his cruise control wouldn't switch off!

Man killed because his cruise control wouldn't switch off!

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Discussion

RB Will

9,666 posts

241 months

Tuesday 29th November 2016
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Started reading this yesterday and being a mk3 Octavia owner and not wanting to die anytime soon I did a bit of experimenting today.

Cruise control - Its impossible to do anything with it by accident as its on a stalk away from the wheel. You can increase speed by pressing the button for it but to decrease you have to cancel it and let the car slow down then set the new lower speed when you get there. You can cancel it anytime.
Cruise control does not accelerate the car hard. It also only cancels on braking. If you have it set and speed up it will stay on then when you slow down it will resume at its set point. This has caught me out a couple of times in the past as I have had it set at about 50, overtaken something then come to a roundabout or junction and go to let it coast down and it just holds at 50, queue some slightly panic'd braking hehe
I'm in a manual not DSG but even if I clutch in and change gear it will resume the cruise speed in the new gear. Obviously with clutch disengaged and in neutral it goes nowhere.

The cruise does not hold the accelerator down. If I set the cruise I can poke at the pedal and it moves up and down with no effect on the cars speed unless pressed down far enough to overcome the set speed of the cruise.

I'm guessing the car in question is a VRS like mine as he mentions taking it out of sport mode, I have 4 driving modes in the VRS. Custom, Comfort, Eco and VRS (Sport) I dont know but would be surprised if any other model varient had the sport mode.

As for stopping it. The brakes are perfectly adequate. I'm running the turbodiesel (184bhp /280lbft) and even accelerating flat out in 2nd gear a hit on the brakes was enough to make the car nose dive and almost cubed my poor dog through her cage in the boot! I wasn't expecting it to stop that hard at full throttle!

Another thing I have been thinking while reading this is if it had been running away for 8 mins why only 119mph?
I have seen 140mph on the speedo and that took less than 1 min at a guess, if it were the petrol version it piles on the speed above 100mph quite a bit quicker as it has another 50bhp.
Will also add in the handbrake is pants. Even on a slightly greasy road at 40mph I couldnt lock the rears, it did still slow the car but nothing like the proper brakes. Might lock them up if yanked hard on the ratchet rather than me just pulling it hard.

My opinion of the whole thing is elaborate suicide. I'm another one confused by how he managed to make it over 10 miles then suddenly veer into the least appropriate object.

TooMany2cvs

29,008 posts

127 months

Tuesday 29th November 2016
quotequote all
RB Will said:
Started reading this yesterday and being a mk3 Octavia owner and not wanting to die anytime soon I did a bit of experimenting today.

Cruise control - Its impossible to do anything with it by accident as its on a stalk away from the wheel. You can increase speed by pressing the button for it but to decrease you have to cancel it and let the car slow down then set the new lower speed when you get there. You can cancel it anytime.
Cruise control does not accelerate the car hard. It also only cancels on braking. If you have it set and speed up it will stay on then when you slow down it will resume at its set point. This has caught me out a couple of times in the past as I have had it set at about 50, overtaken something then come to a roundabout or junction and go to let it coast down and it just holds at 50, queue some slightly panic'd braking hehe
I'm in a manual not DSG but even if I clutch in and change gear it will resume the cruise speed in the new gear. Obviously with clutch disengaged and in neutral it goes nowhere.

The cruise does not hold the accelerator down. If I set the cruise I can poke at the pedal and it moves up and down with no effect on the cars speed unless pressed down far enough to overcome the set speed of the cruise.

I'm guessing the car in question is a VRS like mine as he mentions taking it out of sport mode, I have 4 driving modes in the VRS. Custom, Comfort, Eco and VRS (Sport) I dont know but would be surprised if any other model varient had the sport mode.

As for stopping it. The brakes are perfectly adequate. I'm running the turbodiesel (184bhp /280lbft) and even accelerating flat out in 2nd gear a hit on the brakes was enough to make the car nose dive and almost cubed my poor dog through her cage in the boot! I wasn't expecting it to stop that hard at full throttle!

Another thing I have been thinking while reading this is if it had been running away for 8 mins why only 119mph?
I have seen 140mph on the speedo and that took less than 1 min at a guess, if it were the petrol version it piles on the speed above 100mph quite a bit quicker as it has another 50bhp.
Will also add in the handbrake is pants. Even on a slightly greasy road at 40mph I couldnt lock the rears, it did still slow the car but nothing like the proper brakes. Might lock them up if yanked hard on the ratchet rather than me just pulling it hard.

My opinion of the whole thing is elaborate suicide. I'm another one confused by how he managed to make it over 10 miles then suddenly veer into the least appropriate object.
What happens if you press-and-hold the starter button while driving along?

RB Will

9,666 posts

241 months

Tuesday 29th November 2016
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TooMany2cvs said:
What happens if you press-and-hold the starter button while driving along?
I dont have keyless so cant answer that one unfortunately.

FlyingMeeces

9,932 posts

212 months

Wednesday 30th November 2016
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TooMany2cvs said:
saaby93 said:
Why dont cars have a combined single pedal where full down is fast as you like and full off is brakes locked
Have you ever done a long journey without taking your foot off the pedal for a second or three just to wiggle it around and get a bit more comfy?
That's how most/many hand controls work - forward on the lever is brake, pull back is gas.

Long drives are hard bloody work; the other hand is steering, so best not develop an itchy nose/suddenly realise you need the sun visor etc. yikes

Jimmy Recard

17,540 posts

180 months

Wednesday 30th November 2016
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Diesel runaway seems unlikely for reasons mentioned before - unless that engine holds about ten gallons of oil, I reckon it would've used it all up long before 8 minutes had passed.

El Guapo

2,787 posts

191 months

Wednesday 30th November 2016
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Derek Chevalier said:
croyde said:
I once drove a Ferrari on a track. The owner asked me to remove my right shoe as he said that as the pedals were close together it was possible to press both at the same time and the 500 odd bhp of the engine would easily overcome the brakes.
I'd be very surprised if it could do it in any gear other than maybe 1st.
500bhp engine vs 3,000bhp brakes. No contest.

HorneyMX5

5,309 posts

151 months

Wednesday 30th November 2016
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Jimmy Recard said:
Diesel runaway seems unlikely for reasons mentioned before - unless that engine holds about ten gallons of oil, I reckon it would've used it all up long before 8 minutes had passed.
That engine probably holds a gallon of oil. What sort of live Mpg would you get from one of these under acceleration? 15mpg? So that's more than 10 miles of fuel it's got available. If combined with throttle input from the driver than how long is a piece of string?

B'stard Child

28,447 posts

247 months

Wednesday 30th November 2016
quotequote all
HorneyMX5 said:
Jimmy Recard said:
Diesel runaway seems unlikely for reasons mentioned before - unless that engine holds about ten gallons of oil, I reckon it would've used it all up long before 8 minutes had passed.
That engine probably holds a gallon of oil. What sort of live Mpg would you get from one of these under acceleration? 15mpg? So that's more than 10 miles of fuel it's got available. If combined with throttle input from the driver than how long is a piece of string?
Nick

Diesel on runaway doesn't need a throttle input..... I am with you on the less than 8 mins for the contents of the sump - probably 4 or 5 min max

HorneyMX5

5,309 posts

151 months

Wednesday 30th November 2016
quotequote all
B'stard Child said:
HorneyMX5 said:
Jimmy Recard said:
Diesel runaway seems unlikely for reasons mentioned before - unless that engine holds about ten gallons of oil, I reckon it would've used it all up long before 8 minutes had passed.
That engine probably holds a gallon of oil. What sort of live Mpg would you get from one of these under acceleration? 15mpg? So that's more than 10 miles of fuel it's got available. If combined with throttle input from the driver than how long is a piece of string?
Nick

Diesel on runaway doesn't need a throttle input..... I am with you on the less than 8 mins for the contents of the sump - probably 4 or 5 min max
I agree that it doesnt, but if he was mashing the wrong peddle at the same time in panic he would be literally adding more fuel the fire. I was wondering if this would prolong how far it would run while running on.

B'stard Child

28,447 posts

247 months

Wednesday 30th November 2016
quotequote all
HorneyMX5 said:
B'stard Child said:
HorneyMX5 said:
Jimmy Recard said:
Diesel runaway seems unlikely for reasons mentioned before - unless that engine holds about ten gallons of oil, I reckon it would've used it all up long before 8 minutes had passed.
That engine probably holds a gallon of oil. What sort of live Mpg would you get from one of these under acceleration? 15mpg? So that's more than 10 miles of fuel it's got available. If combined with throttle input from the driver than how long is a piece of string?
Nick

Diesel on runaway doesn't need a throttle input..... I am with you on the less than 8 mins for the contents of the sump - probably 4 or 5 min max
I agree that it doesnt, but if he was mashing the wrong peddle at the same time in panic he would be literally adding more fuel the fire. I was wondering if this would prolong how far it would run while running on.
I see where you are coming from - it's the panic bit I don't get....

8 mins of panic - you've not hit anything you are doing 100 mph or thereabouts - at what point do you stop

I have had moments of panic - about to roll a car - an accident between two lorries travelling in different directions happening in front of you and you are hard on the brakes and looking for the escape, I just can't rationalise that time period of panic

98elise

26,644 posts

162 months

Wednesday 30th November 2016
quotequote all
saaby93 said:
otolith said:
It's the same response, though - they mistake the accelerator for the brake, and their response to the resulting acceleration is to push it harder. It would be very unusual for somebody to go for 8 minutes doing that without realising what they'd done, but then how often does this happen? It's an unusual case.
Why dont cars have a combined single pedal where full down is fast as you like and full off is brakes locked
You would be trying lift off a pedal while the force applied to your body would be pushing you forwards. It would make controlling hard braking interesting.


snuffy

9,796 posts

285 months

Wednesday 30th November 2016
quotequote all
RB Will said:
TooMany2cvs said:
What happens if you press-and-hold the starter button while driving along?
I dont have keyless so cant answer that one unfortunately.
I have keyless entry and this thread has got me thinking about that- but I'm not about to press the button and find out !!


Sheepshanks

32,805 posts

120 months

Wednesday 30th November 2016
quotequote all
snuffy said:
RB Will said:
TooMany2cvs said:
What happens if you press-and-hold the starter button while driving along?
I dont have keyless so cant answer that one unfortunately.
I have keyless entry and this thread has got me thinking about that- but I'm not about to press the button and find out !!
If you press hand hold it for a few seconds the engine will stop. You have to come to a complete stop before you can restart it.

Zombie

1,587 posts

196 months

Tuesday 13th December 2016
quotequote all
Found this thread after it being discussed in the office in work.

I’m going to assume that it wasn’t suicide and that there was an actual fault. This is something that does concern me. Manufacturer’s seem be moving further towards total electronic control of some fundamental systems.

So taking the accident as a example:

I think some key points that have been reported are as follows;

Article states that the Skoda has a push button start rather than a key.

Driver stated :

“It is not letting me stop. It [the speedometer] shows 70mph, but I think I am going much faster than this.”

“I am trying. It is not stopping at neutral.”

Martin Clatworthy stated:

“The car was travelling at 116mph with the accelerator pedal fully depressed five seconds before the crash, while no braking was recorded. It continued to accelerate and hit a top speed of 119mph, with the accelerator pedal pressed two-thirds of the way down. Then just two seconds before the impact, at 94mph (152kph), the accelerator was not depressed at all.”

I’ll admit that whilst I have knowledge of the systems involved, my experience relates to Alfa’s which use generic (mostly bosch) control systems. These may or may not be the same or similar to the Skoda involved.

I think some assumptions can be made about the car based on what has been reported.

Button Start

It’s an automatic. (“I am trying. It is not stopping at neutral.”) – Sounds like he was moving the selector through to neutral and the gearbox was not responding.

Fly by wire throttle – I think almost all modern cars are.

It could have an electronic parking brake


Looking at the electrical systems involved:

The type of engine doesn’t appear to have been identified – could have been a hot petrol version.

I think it’s conceivable the cruise could have failed. All that would require would be the accel button to stick or break.

Another failure mode would be in line with what the driver was saying

“It is not letting me stop. It [the speedometer] shows 70mph, but I think I am going much faster than this.”

Cruise has been set at 70mph and is accelerating to maintain this speed because it thinks it’s going slower.

I think that Cars now generally measure their speed through the abs sensors – so it would have 4 sensors to determine how fast it’s going. Whilst it’s unlikely that all 4 have failed, its worth noting how the systems generally cope with conditions

1 or more sensors fail – ABS light on, reading from that sensor ignored. Cruise control also shouldn’t work.

The system looks at steering angle as part of a stability control set up as well as individual wheel speeds and yaw.

The system will also take readings over longer periods and make adjustments to identify and compensate for (uneven) tyre wear.

Anything wrong with that and again, fault light and cruise should be disabled.

There are also switches above the clutch and brake pedals. These can be adjusted in most cases. I think the clutch switch is generally just a 2 pin on/off jobbie and common sense would dictate that this makes a connection when the pedal is up, the connection being broken when it is down.

The brake pedal is a little more complex. I’ve seen cars with the 2 pin switch as above and 4 pin set ups. One 4 pin set up may use a separate circuit for the brake lights whereas others may use a second switch for redundancy – one off, one on whilst the pedal is either up or down.

Again, any faults here and the cruise system should cut out. Same if a switch is no connected. Having said that, I’ve seen a car where if the switch is connected, the cruise won’t work but it will with it connected.

The Fly by wire (FBW) throttles I’ve looked at have also have two sensor tracks. As the pedal is depressed resistance increases on one side and decreases by a correlating amount for the other side.

Any faults with the FBW system, such as a dropped sensor or the two track resistances not matching up results in the car going to limp mode (severely restricted power that the brakes may easily overcome).

The other thing I’ve found with FBW’s is that they won’t allow you to left foot brake – Brakes on? Engine throttled back.

Same thing with stability control – if that’s activated, it won’t allow you to apply power, so I’d question whether the same result would occur if abs is triggered.

With respect to the gearbox, I don’t know, but I assume some manufacturers have moved on to a totally electronic control? i.e. you move the lever and this just operates a switch below rather than having a physical connection with the gearbox.

I can see a situation where the start button has failed. But again, I would assume that there is some form of redundancy in the button. Although, that may be difficult to achieve, if it does fail, you don’t want the car to cut out in the outside lane of a motorway?
The transcripts reported suggest that this was working so the fault must have been elsewhere.

Then there’s the hand brake. Which could also have been electronic?

Presumably the brakes are not FBW? That they still have a direct mechanical connection with the driver. On that basis I can only assume that they have over heated and boiled the brake fluid.

Throttle position sensors could have failed. That may explain the pre impact readings. But this would require the brakes to have also failed. IIRC, So maybe the brake pressure switch in the ABS had failed and that this was a historical fault?

The braking system may have failed? Maybe a software fault where the speed sensor readings are frozen, making the cruise system think it was going less than the desired speed? If this has failed it’s not inconceivable that other elements involved in apply the brakes could also have failed?

How would this tie in with the gearbox though? It’s difficult to knock a manual out of gear when the engine is under load isn’t it? You have to accelerate and back off to release it.

But the driver said “I am trying. It is not stopping at neutral.” Which is open to interpretation. If it was an auto with a mechanical connection to the box then I don’t see how this would work.

D
4
3
2
1
N
R
P

Is the usual sequence? So going past or not stopping at N would have grenaded the engine. Same applies for the preceding gears. 1st at 100mph should have stopped it.

Which suggests electronic control with some form of intervention. No, don’t be daft you’ll break it.

To me, all of it smacks of a software issue, particularly when you consider the driver is reported as saying;

"I have kept pressing the button, but all it makes is a noise. My speed is increasing. I think what has happened was I tried to change the mode on the car, because I was on the sports mode. I pressed a button to come onto the normal mode and then it is not allowing me to do anything,"

Sports mode could cover a multitude of systems including throttle and gears.

In a car with electronic control over;

Ignition
Gear selection
Handbrake
Throttle

And partial control of the brakes.

It also seems daft to me that there is so little mechanical connection between the driver and a modern car. And very little means to override the electronics.

Zod

35,295 posts

259 months

Tuesday 13th December 2016
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Automatics go PRNDxyz.

Brake pedals are mechanical. He could and should have braked as hard as he could.

TooMany2cvs

29,008 posts

127 months

Tuesday 13th December 2016
quotequote all
Zombie said:
Found this thread after it being discussed in the office in work.

I’m going to assume that it wasn’t suicide and that there was an actual fault. This is something that does concern me. Manufacturer’s seem be moving further towards total electronic control of some fundamental systems.

<big snip>
So, basically, almost everything electronic has gone wrong in a way that's preventing any of the controls from doing anything. This has continued for long enough that he's absolutely cooked the brakes. But whatever electronic's gone wrong, has gone wrong in such a way that the dash isn't lit up like a christmas tree, just a bit pessimistic, and the engine management is still running the car just fine.

Then, after the crash, it was all working again.

Gotcha.

trackdemon

12,193 posts

262 months

Tuesday 13th December 2016
quotequote all
TooMany2cvs said:
Zombie said:
Found this thread after it being discussed in the office in work.

I’m going to assume that it wasn’t suicide and that there was an actual fault. This is something that does concern me. Manufacturer’s seem be moving further towards total electronic control of some fundamental systems.

<big snip>
So, basically, almost everything electronic has gone wrong in a way that's preventing any of the controls from doing anything. This has continued for long enough that he's absolutely cooked the brakes. But whatever electronic's gone wrong, has gone wrong in such a way that the dash isn't lit up like a christmas tree, just a bit pessimistic, and the engine management is still running the car just fine.

Then, after the crash, it was all working again.

Gotcha.
And of all potential places to guide the car, he chose the back of a lorry, guaranteed to decapitate an occupant. As opposed to - oh I don't know - driving up the grass verge into foliage, scraping along the central reservation, or really anything other than the guaranteed insta-death option. Righto

Zombie

1,587 posts

196 months

Tuesday 13th December 2016
quotequote all
If it was a software crash, that affected multiple systems the a reboot caused by the crash could have cleared the original fault?

Zombie

1,587 posts

196 months

Tuesday 13th December 2016
quotequote all
trackdemon said:
And of all potential places to guide the car, he chose the back of a lorry, guaranteed to decapitate an occupant. As opposed to - oh I don't know - driving up the grass verge into foliage, scraping along the central reservation, or really anything other than the guaranteed insta-death option. Righto
Hmmm. That element doesn't make much sense.

Forced into the shoulder by vehicles in all 3 lanes?

Edited by Zombie on Tuesday 13th December 18:34

B'stard Child

28,447 posts

247 months

Tuesday 13th December 2016
quotequote all
Zombie said:
trackdemon said:
And of all potential places to guide the car, he chose the back of a lorry, guaranteed to decapitate an occupant. As opposed to - oh I don't know - driving up the grass verge into foliage, scraping along the central reservation, or really anything other than the guaranteed insta-death option. Righto
Hmmm. That element doesn't make much sense.

Forced into the shoulder by vehicles in all 3 lanes?
The Telegraph Article said:
The coroner was told that a retired firefighter driving an Ocado HGV on the opposite side of the road recalled to police how the white Skoda crashed into the truck 600 yards after the M40 merged into the A40 Western Avenue shortly after 3am.
M40 3am - all three lanes filled........

He was travelling for 8 mins at speeds above 70mph (according to the phone log)