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Comment by travelton | Hacker News Reader

"Catastrophic Failure" sounds a bit dramatic.

The car could no longer drive. Short of bursting into flames that’s about as bad as it gets.

I think catastrophic to me would involve some sort of destruction of the car. Like it exploding or something.

That was what I was imagining when reading the headline. The battery had spontaneously combusted or something like that.

I think you're downplaying the number of cars that actually do burst into flames. A car telling me it can't run seems quite undramatic.

So what would constitute a normal failure? Because I wouldn't consider it a failure at all unless I couldn't drive.

If you are late to work because your car won't start, say a bad starter or a dead fuel pump, would you really tell your boss that your car had a "catastrophic" failure?

TFA mentions a "pyrotechnic battery" which sounds like a great feature for a military fort but not so much for an automobile?

It was a "pyrotechnic battery disconnect", i.e., basically a type of switch/active fuse using some type of small explosive charge as part of its operation.

Here's the patent for all the gory details:

https://patents.google.com/patent/US9221343

The fact that this part has a "problem" probably means that it was triggered, e.g., maybe some type of false collision detection, short circuit or other failure which ended up triggering the disconnect.

"Disconnect" also belongs to the expression - essentially, a tiny explosive is used to ensure that the safety switch disconnects the battery from the load side, permanently and without arcing: https://insideevs.com/news/334322/tesla-patents-pyrotechnic-...

A pyrotechnic battery disconnect, which I suppose cuts the connection to the battery instantly in case of accident to avoid shorting it. There are already pyrotechnic devices in cars: airbags are pyrotechnic, as well as safety belt detents. It's the fastest type of actuator.

Yeah, I totally expected there to be some kind of injury or at least a threat of it involved. But I'm not a frequent driver so I guess I cannot relate to these "catastrophes" as well as I could.

"Catastrophic failure" is a common engineering term that essentially means "complete and irreversible failure."

For a regular car when I hear catastrophic failure I think scrap metal in the oil pan.

Are you sure? A catastrophe is often defined as “A complete failure” and the car certainly meets that criteria.

More like irreversible, total destruction.

It may have been catastrophic for his afternoon plans, but the car has clearly be repaired.

yeah, they got the 2020 equivalent of a blinking engine check light, but !on a Tesla! so it's a blog post and on the front page nonetheless

According to you the 2020 equivalent of a blinking engine light is an immobilized vehicle.

That alone is worthy of a blog post on the front page if it were true (it's not).

you are supposed to call a tow with a blinking light, so yeah. hardly different

> you are supposed to call a tow with a blinking light

Citation needed.

just open your owner manual, for most cars is standard

steady light: maintenance

flashing for a time: issues on the emissions controls, you risk on the long run to damage the converter or stuff like that

fixed flashing light: something seriously wrong, like a misfire or worse, running the engine is actively damaging it. car runs in protected mode as not to leave you stranded in a dangerous situation, but you are not supposed to run it.

what's your car if I might ask?

Citation from the 2003 SL55 AMG owners manual under "what to do if ... the yellow check engine indicator light comes on"

  Have the vehicle checked as soon as possible by an 
  authorized Mercedes-Benz Center.  An on-board diagnostic 
  connector is used by the service station to link the
  vehicle to the shop diagnostics system. It allows the
  accurate identification of system malfunctions through the 
  readout of diagnostic trouble codes. It is located in the
  front left area of the footwell next to the parking brake.

And this is only after checking the fuel cap and ensuring the fuel tank isn't empty.

They don't recommend towing the vehicle. There are surprisingly few conditions mentioned in the manual where a tow to the service center is recommended: brake system failure indicators, and visibly dangerous tire damage/vibrations.

There is however substantial discussion of towing methods and proper towing procedure, mentioning significant risks of damage when done incorrectly. So we see, towing isn't some kind of panacea the manufacturers are eager to suggest - the process may break things like the transmission or body if done incorrectly, especially over long distances.

It's a noteworthy difference in the failure modes of Teslas (and perhaps EVs in general) vs. conventional ICE vehicles.

ICE vehicle drivetrains often fail more gracefully. The first vehicle I purchased, to rebuild before getting a driver's license, had a broken con-rod, yet it still drove noisily with a hole in the side of the engine block.

ICE vehicle manufacturers do not actively disable a vehicle in a CEL-triggering condition. They want nothing to do with potentially pro-actively stranding someone, which could be a life-or-death situation like a snowstorm, just because some sensor is malfunctioning on an otherwise perfectly operable automobile.

Requiring a tow is a self-evident condition. It's been generally left up to the owner to decide if they want to risk potentially costly repairs driving with an indicator light flashing.

I dunno where you can look it up, probably a modern car manual, but as someone within an entire family of mechanics, ive never heard of a blinking check engine light that didn't mean your shit is seriously fucked up and any second away from blowing apart. In fact blinking check engine lights are pretty new overall to differentiate between shit like 'this light is on because your o2 sensor is going bad' and 'this light is on because only half your motor is getting enough oil', now it blinks with the oil problem so you know it is serious. Although a number of cars these days have completely separate 'service engine' and 'engine warning' lights so a blinking check engine light might not exist for whatever model.

If anything other than your blinker blinks more than a handful of times past startup, something is very very wrong.

thank god there's a second car person around here, it felt lonely.

I was sort of expecting the car to have exploded, parts strewn about, and the steering wheel missing. Nope, just a check engine light.

I've collected more miles on my last car with the engine light on than off. Earlier you could at least override false positives by just not caring.

on is different than blinking

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