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Re:Toyota's firmware: Bad design and its consequences by makerops on Tuesday October 29, 2013 @04:34PM (#6637239)
I was always taught that the mechanical override was shifting it out of drive and into neutral.
Re:Toyota's firmware: Bad design and its consequences by michael_h on Tuesday October 29, 2013 @04:42PM (#6637285)
This is true for most vehicles, but on some cars (like the Prius) the shifter is not mechanical.

Yes, it's unnerving.

Re:Toyota's firmware: Bad design and its consequences by drbawb on Tuesday October 29, 2013 @04:58PM (#6637372)
The list is only growing longer . . .

If you have computer-assisted hill starts, collision avoidance, or computer assisted braking [through ABS, certain traction & stability control systems, etc] your computer has control of your brakes.

If you have range-assisted cruise control, or early collision alert, your computer likely has total control over your throttle.

If you have parking assist, lane departure warning, lane following assist, or electric power steering etc: your computer has control over your steering.

If your car has a DCT: your computer has control over your shifting _as well as both clutches._ -- Meaning you have _no mechanical interface_ to disengage the motor from the transmission. This is similar to your Prius example: the shifter is not mechanical.

On many new cars: there's no ignition key to remove. You likely have a smart "keyfob" that simply needs to be within X-feet of the car, and then you have a push button ignition.

I'm sure there's some override for the button [push and hold for three seconds], but it's still going to go through some electronics to figure that out.

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The only bit that scares me is that all these systems potentially share the CAN bus with the horrendous "Infotainment" systems that every manufacturer loves to install. shudders

Re:Toyota's firmware: Bad design and its consequences by fnordfnordfnord on Tuesday October 29, 2013 @05:10PM (#6637455)
Mfrs have started using LIN for slow-control accessories like power windows, door locks, wipers, etc. A separate CAN for critical functions of the auto, and another (sometimes CAN) system for non-critical things like GPS integration, entertainment, and (apparently) MOSTbus has finally taken off after much teeth gnashing. MOST is a higher bandwidth than CAN bus system designed for 'infotainment' systems in autos. https://en.wikipedia.org/wiki/MOST_Bus
Re:Toyota's firmware: Bad design and its consequences by drbawb on Tuesday October 29, 2013 @05:37PM (#6637659)
Thanks for sharing!

I have to admit though I'm surprised that some of those accessories even require a bus as they're typically operated by simple switches.

I guess door locks, wipers, etc. make some sense: with the prevalence of central locking, as well as wipers that sense rain and things like that.

Windows are a bit odd, as they just need a very simple switch. I suppose having all the accessories on a common bus must simplify the wiring harness though.

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I'm curious how TESLA integrates their in-dash system with the rest of the car.

I thought their in-dash console could control some rather safety-critical "preferences" of the car ... for instance I thought you could adjust the level of regenerative braking.

(Other manufacturers are also offering "sport modes", etc -- though they're not always controllable through the dash.)

Re:Toyota's firmware: Bad design and its consequences by fnordfnordfnord on Tuesday October 29, 2013 @06:11PM (#6637865)
>I have to admit though I'm surprised that some of those accessories even require a bus as they're typically operated by simple switches.

They certainly don't require a bus in principle. However, if you want to understand both the business case and some very good engineering reasoning behind the use of data buses to control simple automobile accessories you should have a look at the wiring harness for an early 90's Mercedes or similar luxury car. Demand for fancy features drove the number of wires running to and fro to an unmanageable level. Having a mile of wires in a car is expensive for many reasons I'm sure you can imagine, as well as each connection point becoming an opportunity for something to go wrong.

I'm also curious how electric cars in general will manage safety systems going forward, especially in light of this Toyota court decision.

Re:Toyota's firmware: Bad design and its consequences by lsaferite on Wednesday October 30, 2013 @12:10PM (#6641232)
One example of where a CAN/LIN bus connected power window is good is my old Jetta. You could insert the key in the driver door lock and turn it backwards to make the car roll down all of the windows and open the sun roof. As someone else mentioned, you can likely implement features like this via hard wiring, bu then you get massive wiring harnesses.
Re:Toyota's firmware: Bad design and its consequences by msandford on Tuesday October 29, 2013 @04:57PM (#6637364)
That's why you buy a car with a manual transmission. Those haven't been electronic-ized yet and are unlikely to be as the forces involved in depressing the clutch are substantial and unlikely to go away.

Once the clutch plates are no longer in contact the engine can do whatever it wants but none of that makes it to the wheels. And then you can get the car out of gear to coast, turn the whole car off and then back on.

There's no substitute to having a human being in the loop to execute high-level "executive" functions, especially when things aren't done to the very high standards of aerospace. You know, like cars.

Re:Toyota's firmware: Bad design and its consequences by drbawb on Tuesday October 29, 2013 @05:02PM (#6637400)
> That's why you buy a car with a clutch pedal.

There exist "manual transmission" that lack an operator controlled clutch. DCTs are very much manual transmissions, but many of them rely on a TCM to disengage the clutches.

Re:Toyota's firmware: Bad design and its consequences by bri3d on Wednesday October 30, 2013 @06:07PM (#6643779)
I do agree that having a hydraulic (or cable)-clutch car eliminates the ECU from a critical path (power to wheels), but there are plenty of electronic-ized manuals.

There are all sorts of advanced DSG / dual-clutched transmissions in many newer cars, but even some older cars like the MR2 and Smart cars have a http://en.wikipedia.org/wiki/Electrohydraulic_manual_transmi... : quite literally a manual transmission where the clutch has been actuated electronically.

Re:Toyota's firmware: Bad design and its consequences by matt-attack on Tuesday October 29, 2013 @06:42PM (#6638031)
I agree. With a Camry, shifting into N would have immediately remedied the problem. I remember hearing reports claiming: "Shifting to N didn't do anything".

The explanation always seemed obvious to me: Non-technical driver experiences UA. In a panic shifts into neutral. Hears engine scream. Thinks, "The car is still going!" and doesn't realize that despite the sound, the car is actually slowing down.

I know this to be a common misconception in my experience. People commonly misinterpret high revs with "going fast".

Re:Toyota's firmware: Bad design and its consequences by drbawb on Wednesday October 30, 2013 @11:48AM (#6641102)
Oh wow, good point, I hadn't thought of that. "High revs" = "motor going fast" to me, not "wheels going fast."

But I had not considered that this correlation is only intuitive to me because I own a car with a manual transmission.

Re:Toyota's firmware: Bad design and its consequences by Zancarius on Wednesday October 30, 2013 @09:21PM (#6644692)
I'd imagine the sudden loss of power should be apparent as well.

But then, people can react irrationally (or not at all) in a full on panic.