3 ms·

Cars often disable any system capable of interfering with the wheels at the least sign of issue. Insufficient seal on the fuel-cap? Disable ABS, TCS, etc.

nradov 11y ago
That's not correct. You can leave the fuel cap off and it won't disable ABS or TCS. The only thing that will happen is the "check engine" warning light will come on.
acranox 11y ago
That's not correct. Cars will generally have something that's often called a 'limp home' mode. I saw a car that's PCM (powertrain control module) that failed some internal test, so it fell back to a basic mode where the engine wouldn't rev over about 2000RPM, and I'm sure all the emissions systems went into a basic fail-safe mode, where things like the fuel delivery goes into a hard-coded mode, instead of using feedback from the oxygen sensors to tune the fuel delivery. But a loose fuel cap doesn't disable the ABS or TCS. Even a single faulty wheel speed sensor doesn't have to disable the entire ABS, it can still independently assess each wheel, determine if a lock-up is imminent and modulate the brakes for that wheel.
- mturmon 11y ago
  That's neat. The counterpart for spacecraft is "safe mode" (http://en.wikipedia.org/wiki/Safe_mode_(spacecraft) http://en.wikipedia.org/wiki/Safe_mode_(spacecraft) ). The priorities are maintaining attitude control, conserving power, and listening to the radio. The science instruments and other bells and whistles are turned off as much as possible.
damoncali 11y ago
Funny. Just the other day, my gas cap was loose. The traction control light came on along with the check engine light. As far as I could tell, it (traction control) was still operational, however. Seemed like a funny combination of lights to blink on.
_nedR 11y ago
What really scares me are the ABS and traction control systems that are now becoming mainstream on motorcycles. These systems have accelerometers and gyros, which take in to account, information like lean angle of the bike when calculating the braking force. It certainly is a feat of engineering. Little about being a biker, programmer, and an aspiring tree-shade mechanic, reassures me about the safety of these systems. Internals of a bike are much more exposed to abuse, bikers are known to take a spanner to their machines, the motorcycle repair workshops are a much more informal industry (at least here in India). What happens to a bike that is not subject to regular maintenance? On the other hand, I have always marvelled at how mechanical systems like motorcycles are usually built with some sort of graceful failure in mind - In a lot of cases a motorcycle will warn you about a faulty component before it fails catastrophically. I assume the people who designed these systems, would have kept that in mind while designing these systems (although stuff like Toyota's unintended acceleration does not inspire confidence). And what happens in the event of a catastrophic failure:- a car locking up at speed is still dangerous, but there is room for error. If the front tires of your motorcycle locks up at speed, the odds of you walking away from the incident are not high. Don't get me wrong, these systems DO SAVE more LIVES than they could possibly take away in the long run, But I am still disconcerted by the whole thing. EDIT: typos
- takeda 11y ago
  > although stuff like Toyota's unintended acceleration does not inspire confidence Another thing that worries me are that these same companies are also working on self driving cars. Worst of it is that everyone pretty much jumped into the race after Google. It also doesn't look like existing solutions work on a real time system. I'm a bit worried about being hit by a car because it was running garbage collection process and did not react quickly enough.

nradov 11y ago

That's not correct. You can leave the fuel cap off and it won't disable ABS or TCS. The only thing that will happen is the "check engine" warning light will come on.

acranox 11y ago

That's not correct. Cars will generally have something that's often called a 'limp home' mode. I saw a car that's PCM (powertrain control module) that failed some internal test, so it fell back to a basic mode where the engine wouldn't rev over about 2000RPM, and I'm sure all the emissions systems went into a basic fail-safe mode, where things like the fuel delivery goes into a hard-coded mode, instead of using feedback from the oxygen sensors to tune the fuel delivery. But a loose fuel cap doesn't disable the ABS or TCS. Even a single faulty wheel speed sensor doesn't have to disable the entire ABS, it can still independently assess each wheel, determine if a lock-up is imminent and modulate the brakes for that wheel.

mturmon 11y ago
That's neat. The counterpart for spacecraft is "safe mode" (http://en.wikipedia.org/wiki/Safe_mode_(spacecraft) http://en.wikipedia.org/wiki/Safe_mode_(spacecraft) ). The priorities are maintaining attitude control, conserving power, and listening to the radio. The science instruments and other bells and whistles are turned off as much as possible.

damoncali 11y ago

Funny. Just the other day, my gas cap was loose. The traction control light came on along with the check engine light. As far as I could tell, it (traction control) was still operational, however. Seemed like a funny combination of lights to blink on.

_nedR 11y ago

What really scares me are the ABS and traction control systems that are now becoming mainstream on motorcycles. These systems have accelerometers and gyros, which take in to account, information like lean angle of the bike when calculating the braking force. It certainly is a feat of engineering. Little about being a biker, programmer, and an aspiring tree-shade mechanic, reassures me about the safety of these systems. Internals of a bike are much more exposed to abuse, bikers are known to take a spanner to their machines, the motorcycle repair workshops are a much more informal industry (at least here in India). What happens to a bike that is not subject to regular maintenance? On the other hand, I have always marvelled at how mechanical systems like motorcycles are usually built with some sort of graceful failure in mind - In a lot of cases a motorcycle will warn you about a faulty component before it fails catastrophically. I assume the people who designed these systems, would have kept that in mind while designing these systems (although stuff like Toyota's unintended acceleration does not inspire confidence). And what happens in the event of a catastrophic failure:- a car locking up at speed is still dangerous, but there is room for error. If the front tires of your motorcycle locks up at speed, the odds of you walking away from the incident are not high. Don't get me wrong, these systems DO SAVE more LIVES than they could possibly take away in the long run, But I am still disconcerted by the whole thing. EDIT: typos

takeda 11y ago
> although stuff like Toyota's unintended acceleration does not inspire confidence Another thing that worries me are that these same companies are also working on self driving cars. Worst of it is that everyone pretty much jumped into the race after Google. It also doesn't look like existing solutions work on a real time system. I'm a bit worried about being hit by a car because it was running garbage collection process and did not react quickly enough.