Years back I met a brake failure (I was 20 then) and ended up hitting an auto rickshaw from behind. The car in question was a corolla D-4D and it was a manual without cruise control etc. Here is a link to the incident:
Brake Failure Incident
After that particular incident, I have done a bit of research on brake failure and accelerator + brake situations and drew out a couple of conclusions too. In fact I have ended up making a couple of discoveries too during the experiments I conducted with hand brake etc.
RIP the departed soul, 8 minutes of trauma was enough to make anyone go out of senses. There are only two probabilities:
1) Electronics taking over everything
2) Incomplete knowledge of the system.
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Originally Posted by veedub89 In a car with a start-stop button, the key needs to be present inside the car for it to start. So if you throw the key outside, the engine might cut off. Not too sure about this though. |
Well, sir if you throw the key out; absolutely nothing will happen. Just wish that the car won't bog down after going a kilometer or two. Don't ask me how I know this, I have paid by being fooled at a signal after playing mischievous with a friend. Accidentally turned the engine off, and then it started asking for the key!
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There are other ways too. You could potentially start scraping the car into the guardrails present on most highways. The frictional losses should give some deceleration.
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The result could have been something like this (Definitely not recommended. For a solid median, it can be done) :
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Maybe hitting a moving lorry could also help. The relative velocity will be lesser and the impact should disable the car's systems. The guard rails will prevent the car from going beneath the lorry.
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In case everything seems to be out of control, hitting a fast moving lorry or bus from behind can be the safest possible option IMO.
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Originally Posted by SchumiFan Hitting the brake pedal cancels the cruise control. Also one can switch off the thing completely. |
I guess it was an electronic malfunction. Maybe some wrong feedback signal from any sensor has rose up a bug in the code.
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Was hand breaks not working too?
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I don't think Octavia has electronic handbrake, the mechanical one must perfectly work here but won't help until the engine stops pulling.
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Would have paddle shifts worked? If he had shifted down manually using paddle shifts?
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I have tried this once (Maybe it works on DSG) but the pedal shifters won't shift lower than the minimum possible gear ratio required to maintain the speed the cruise control is engaged to work at.
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Originally Posted by shifu There can be a lot of 'what-ifs', but from the underlined sentence above is it possible that there was some loose floor mat or something that depreseed the accelerator pedal and the driver attributed the acceleration to the cruise control? |
There is a huge possibility of that too. What has rose my eyebrows is the fact that accelerator pedal was fully depressed. If it was a mat or stuck pedal then how it got released 1.5 seconds prior to the accident? Additionally the accelerator pedal can't be fully depressed earlier too, else the car would have hit the top whack of it easily in 8 minutes. Maybe in desperate attempts to get things under control, he tried to press accelerator pedal too with a bleak hope that it may disengage the devil.
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Originally Posted by greatestmj Today I tried a few things in my Honda City Automatic. I went to low traffic 4 lane road and at speed of 70-80 kmph I pressed start stop button once. Nothing happened. I then pressed twice and my car shut off. But I could still steer a bit and safely went off lane to sides while car was slowing down due to friction maybe. Then I tried breaks too, it was partial breaking as well. I didn't have much guts to slowly try hand break as I thought its risky.
At 70-80 I also tried using paddle shifts and downshifted slowly from 7th to 6th, 5th eventually till 3rd and each downshift was slowing down the car. If someone is in trouble downshifting can help, it may hurt the gearbox if you downshift to 1 or 2 but Atleast person can be safe? |
One can try the following while having their car parked:
- Turn the engine off and press the brake pedal multiple times. Initially it will go down completely like it does while driving with engine ON. Then it starts becoming hard with each pumping you do.
- Turn the steering wheel within say 5 seconds of turning the engine OFF, it still has a bit of assist and you an turn it quite easily. Additionally on a running car, even if the assist fails, the steering wheel still works.
What my experience says is that even if you turn off the ignition by continuous pressing of button or via the key, you still can brake the car as the first pump will give you enough of the braking force Not releasing the pedal will keep the shoes stuck to the disc quite firmly giving you enough of the stopping power to come to a halt. Additionally hand brake can help, but one needs to be very cautious with this stick. If the handbrake is an electronic unit, better don't even think about it. If it's a mechanical one then pull it to the point where it starts becoming tight (The point where shoes start braking but don't lock) and leave it at that position itself so that you can have braking force as well as control altogether; this method needs a long distance to come to a halt from 100 kph though, if being done on an automatic car in N mode.
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Originally Posted by StarrySky The driver or the 999-operator may not have been aware of this. Even I wasn't, till I checked the manual again today. So, we cannot be sure if there was a starter button failure. |
Quite a possibility, user manuals are read by fewer than a few after all.
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Originally Posted by Akshay1234 1) Shift to neutral - Shifters usually depend on the brake pedal being pressed, and the shift lock button being pressed too. But normally to shift from D to N the shifter can just be moved up, without requiring anything else. |
There is a probability of the shifter sensors gone bad (It is basically nothing but a shifter position sensor only after all). If a sensor is gone bad then even if you shift to R; it won't work.
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2) Downshifted the gear - Moving the gearbox into manual or using paddles would have downshifted the gears. I can't imagine how this didn't work either.
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I have personally tried it, it doesn't work. If cruise control is engaged then it only shifts down to minimum ratio required for that speed. Say third cog at 120 kph for Octy 1.8. But I haven't tried it in a dual clutch one and won't recommend anyone doing it with a DSG (They are already delicate gearboxes). For TC and CVT boxes, it is the way I have mentioned; but I can be wrong, I haven't driven every car with TC or CVT after all.
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3) Braked - I am of the understanding that vehicles brakes are always more powerful than the engine. Meaning if the brakes were fully jammed, they would slow down the car even if it were at wide open throttle. And in this case the vehicle was not at wide open throttle, because it was doing 150 odd kmph when it crashed.
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With due respect sir, you are absolutely wrong here. For the cars like Alto 800; it can be possible. For a car with an engine like 1.8 TSi or 2.0 TDi; the torque from engine (Gearbox and final drive already multiplies it a lot) is more than enough to prove the brakes puny. Going by the FOS; the propulsion shafts are strong enough that they also won't wreck and keep transmitting the torque to the driving wheels with brakes simply keep on burning. The cruise control will detect the load (It's a simple looping function + fuzzy logic), shift down a cog and the engine will pull harder. Then it will shift an another gear down and the massive wave of torque from engine will simply dwarf the brake force.
For a RWD car, pressing full brakes and full throttle won't do anything (I have done this with a Safari VX). The engine will drive the rear wheels and ABS will make sure that front wheels also will initially brake and then get back into a speed synchronous to the rear ones. For a FWD car, the handbrake can be pulled at max with brakes; the rear wheels may get locked at max, either the tyres will burn or the vehicle will overturn. But if the engine is powering the wheels (That means no neutral possible), and is not under control, the the driver can at max steer it into some obstacle like a fast moving truck. It's like selecting the smaller of the two evils.
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4) Put off the engine - Again all vehicles do put the engine off even if moving, by holding down the starter button.
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Probability of insufficient knowledge here.