Why Not A Kill Switch?


I just got to thinking about this the other day, with all the talk about out of control cars and the like. Why not put a kill switch on today’s cars? With all the safety features available nowadays I’m surprised no one has actually come up with this. Maybe like a big red button on the dash that you could push in event of emergency or accident that would cut power to the engine. Have it under a transparent cover that you flip up so it isn’t accidentally triggered by bumping. Motorcycles & jet skis have them among other things. Seems like a fairly simple solution.


I think the trouble is that you can’t trust the average motorist to distinguish an emergency in which you should turn the engine off and an emergency in which turning the engine off will make things much, much worse. It’s like how some people’s first instinct with the runaway cars is to pull the emergency brake, even though there’s absolutely nothing wrong with the brakes.

But it does seem like they need to make the cars that have the stupid electronic on/off buttons easier to turn off.


The kill switch on a vehicle that does not need power brakes/steering it is mechanically simple. On a car…I think you have to start talking software again…square one.
The only solution I can see is what’s used on fly by wire planes, redundant computer/software with mechanical/hydraulic back up where possible. Electronics are cheap, mechanics are expensive. Are you ready to pay more ?

The simple solution I feel is…electric or hydraulic traction drive motors to eliminate 90% of the computer controlled complexity and allow redundancy with the few remaining.

Besides, are you willing to drive with that ugly red lanyard on your wrist…do you even now on your toys ?


My vehicles all have kill switches. They’re located on the right side of the steering column where you insert the ignition key. Turn the switch to “off” and it kills the engine. Simple and effective.

IMHO, push button start-stop systems are not an improvement on the standard ignition switch and key.


Already there, either the key or the start/stop button, just have to learn to hold the button down for the 2-4 seconds needed to shut down the engine. But shutting down the engine will usually be the wrong thing to do, shifting into neutral would be the right thing to do.


Any car with a simple key-activated ignition switch has a kill switch already. The problem is that a kill switch would cut power to the power steering and brakes. Motorcycles have an engine cut-off switch because they don’t have power steering, and many smaller bikes don’t have power brakes. Also, using the motorcycle’s engine cut-off switch keeps the electrical power on.

A kill switch in a car would need a cover over it to make sure it didn’t get pressed accidentally, which would make it no more effective than turning the car off with the key.


I agree, those push button ignition systems are just examples of over-engineering for engineering sake. I don’t see any vast improvement. If anything, I feel like I have less control of a car with push button ignition ie, Nissans.


I guess in a perfect world we would need one that would kill the engine but keep power to the brakes & steering, not be unattractive, and not add to the cost of the vehicle. Is that too much to ask?? lol


If the electronic controls on today’s cars (throttle by wire) are going to become more and more prevalent perhaps a variation on the old “kill switch” is something to consider.

What about an “emergency” switch that would override all electronic controls and put the motor in idle mode. Not a complete shutdown of the motor. With the motor idling you still have power steering and power brakes. Hardware and software for such an emergency button or switch shouldn’t be either difficult or expensive.


Most makers, and now Toyota, have throttle override in the software: pushing on the brakes kills the throttle. Only just now added by Toyota, unfortunately!


My car (a Ford Focus) has a “Fuel Pump Shut Off Switch” in the passenger compartment. Am I right in assuming no fuel=no engine revs? Of course, I have never tested it.


I don’t think you can shut off the fuel pump with the switch. It’s an inertial switch that cuts power to the fuel pump if you’re in an accident (so it doesn’t spray fuel all over the place). They’re kind of touchy though and can be triggered by things like hitting a nasty pothole, so that button in the back is so you can reset it when it goes off when it’s not supposed to.


The thing is that the power brakes and power steer are run by the engine (by a belt-driven hydraulic pump in the case of steering, by engine vacuum in the case of the brakes), so if you shut off the engine, you shut off the power assist.

Some vehicles are coming with electric power steering now and cars like hybrids that sometimes run without the engine running have alternate vacuum sources, so it is possible. But, like the others have said, there’s safeguards that are easier to implement. Plus, runaway engine events are extremely rare, even on the Toyotas affected by the current problems, so it’s generally not going to be something to design a whole car around.


Will consumer rejection of push button ignition switches send this enginnering away like it did digital spedometer displays and “heads up displays” on some GM vehicles?

Was the consumer consulted is any way (be it a survey or by some type of exploration as to what customers want in regards to features on their cars) Does anyone like the push-button start technology? If no, let it be known.

I don’t see the validity in the claim that if a kill switch was installed (which I don’t support) that people would not have enough steering or braking to get the vehicle steered or stopped. We are talking about just getting to the shoulder, that’s all.


I don’t see any problem with experienced drivers either, but people would need to know if they engage the switch they would have to steer and brake harder than normal. I think using it a couple times out of traffic in “practice” would be the best idea.


We are talking about just getting to the shoulder, that’s all.

Oldschool, we are talking about a little more than that.

Imagine, if you will, you are in a car in which you lose throttle control and you experience unintended acceleration. If you happen to be on a deserted road with nobody else in your vicinity, or on a two lane road, you would be right.

If, however, you are in the middle of rush hour traffic in Houston (with no left shoulder) on a twelve lane highway when it happens, and find yourself in the fast lane, negotiating your way all the way across six lanes to get to the shoulder could be more daunting than you think.

Think about it. With your engine off, your car would be slowing down, and traffic would be zooming by on your right pretty fast, including those who are passing you on the right from behind. Having fine control of your steering might be pretty important, don’t you think?


Use a latching pushbutton similar to some flashight switches wired to cut power to the electronic throttle body. This will not stop the engine but will instead allow it to return to idle, bypassing the computer. This is what Toyota will do as some others already have, using the brake pedal switch. That method, however, seemingly will not bypass the computer but is a step in the right direction.


And next…transmission by wire, already in some cars. What’s next, steering ?
I think manually controlled cvt can go along way to regain control given up to the computer. Engine rpm could be altered by load automatically instead. Transmission control, I feel, is a key to safe emergency control of speed, not just engine control.


“What’s next, steering ?”

You HAD to ask!


One wonders if that Lexus has the “auto parking” feature, or just a screwed up steering rack?