[hghid]

According to the car, the stability control system wasn't working. Cause? Obviously a broken fuel injector. The stability control system talks to the engine ECU to control the torque if there is a lack of traction - it is notified of this by the ABS computer. Broken Injector=No ability to manage torque, hence traction control warning. Sitting here now, that makes perfect sense. In horizontal Scottish rain - less so!

[uriah]

Unless I’m missing something, it seems that this information largely invalidates the thesis of your previous post. A critical component (fuel injector) failed, the software in the car prevented it from running and causing catastrophic damage. Roadside assistance came, immediately determined it can’t be fixed on the side of the road and towed the car. Seems like a best-case scenario given the circumstances other than possibly the red herring related to the stability control.

[thescriptkiddie]

Assuming that the fuel injector wasn't stuck open, the car could simply disable the affected cylinder and continue to run (poorly) in limp mode. I had exactly this happen in a 20 year old VW and it turned out that the injector was fine and the connector had just come loose. The engine sounded awful running on 3 cylinders and wouldn't go past 3000 rpm but there was no permanent damage. The fault code in the ECU correctly identified the problem (fuel injector cylinder X open circuit) though it did also log misfires and disable traction control.

[ilyt]

Oh yeah, less computers in car wouldn't fix it.

Sure, old carbie with distributor might've just ran with 3 cylinders , but that also might damage something.

Also auto makers don't really want to give user sensible error messages or even just metrics because without experience they might just misinterpret it as different problem.

For example if car have oil pressure gauge it is either nearly fake or heavily filtered. Oil pressure changes according to load but gauge going up and down might cause user to think something is wrong with car...

[ClumsyPilot]

> Sure, old carbie with distributor might've just ran with 3 cylinders , but that also might damage something

A car is not an iPhone - if the car can move at all, it must move.

The alternative could be freezing to death. What if I am driving in rural Siberia, or Canada, and there is no phone signal to call for help?

[pas]

Not all cars are made equal. Just as you don't go to a cross-Sahara race in a car you don't know you, you don't buy a Prius to go logging in Alberta or Yakutsk.

Sure, that doesn't necessarily invalidate your argument, after all this increase in car complexity (through "electronization" and smartification of more and more components) without the increase in debuggability/repairability is IMHO a bad trade-off for many consumers.

Case in point, our second-hand 2011 Ford Focus has a problem with the electronic steering assist. Apparently it somehow experiences some kind of over-voltage and the internal system shuts down. It's likely due to humidity. (So probably it's simply a design/manufacturing/QA issue.) Okay, but there's no way to get the actual data from the integrated electronics from the steering system, but it's possible to reflash a different firmware on it. Which resets the internal data. Which basically clears this error state, and the car will happily use it.

But there's clearly a mechanical error, there's a new "bad" noise when turning the steering wheel. But it's a 10+ year car, rarely used, and replacing the steering system is about ~1000 EUR, doing the firmware flashing was ~30 EUR. (Finding the guy with the laptop, who can flash the firmware through the good old ODB port was the challenge.)

And it's basically a big (market) information asymmetry problem. The car industry wants to sell more cars. Sure they sell some parts, but the more repairability a car has the less parts it really needs, as consumers can make their own tradeoffs.

[hinkley]

My car has a button for traction control. If it’s not working I would expect it to turn itself off and ding, not just halt the vehicle.

[BenjiWiebe]

A bad fuel injector should usually be a reason to stop driving. Depending on the type of damage it would likely damage the piston and/or cylinder fairly quickly if you attempted to keep running it.

[jsmith45]

That would obviously depend on the failure mode. But there certainly are failure modes which could be quite damaging, and an ECU may have limited ability to determine what failure mode is occurring, and even if it has sensors that can indicate certain failure modes, it is not always clear if those can be trusted, as they there be additional failure modes that make sensors give misleading results.

So shutting it down certainly seems sensible.

[ClumsyPilot]

There are situations where you must run the car, even at the risk of damage, because waiting for help is dangerous to the occupants.

[Too]

Cars have a “limp-home” mode which they enter if sensors show odd yet not critical errors. Usually it restricts the acceleration and top speed to 30kmph or so. If it totally shut down it was likely a very serious error.

[danuker]

But what cash grabbing opportunity would the dealer have in that case?

[gnufx]

That sounds horribly familiar! (Old, relatively non-fancy, Ford Focus; it limped along with the failure.) The explanation makes sense, which it didn't at the time, and the traction control button didn't help. The specialist garage initially said "sensor failure", as I assumed, having lost my OBD device.