Do we have brake override?

[BLH]

In the automatic. The shift selector tells the ECU to change to neutral. Get the ECU confused enough and maybe it will not shift into neutral. Manuals no contest. Move to neutral it is in neutral.

[sbergman27]

Originally Posted by BLH

In the automatic. The shift selector tells the ECU to change to neutral. Get the ECU confused enough and maybe it will not shift into neutral. Manuals no contest. Move to neutral it is in neutral.

But what if the manual transmission's shift lever jams? What if I'm in an elevator and the cable breaks and all the secondary safeguards malfunction? What if I'm having dinner in a revolving restaurant and there's a power surge which slings me through the window to my death, while the remaining diners must deal with the Ginsu Knives that come flying out of the kitchen as the restaurant spins up?

Or maybe... just maybe... none of these things are very likely? Maybe people are simply irrationally distrustful of software. And maybe... just maybe... the historically dismal quality of consumer grade software like... well... Microsoft Windows... has done a lot to fuel that irrational distrust.

But the embedded software world is a completely different ball game. Particularly when that embedded software is controlling critical systems. People view the ECU as though it's running the same slap-dash software as their ever-problematic laptops. And it just ain't so.

-Steve

[fmicle]

Originally Posted by sbergman27

Maybe people are simply irrationally distrustful of software. And maybe... just maybe... the historically dismal quality of consumer grade software like... well... Microsoft Windows... has done a lot to fuel that irrational distrust.

I beg to differ... No need to bash Microsoft here Why is almost 90% of the world using Windows? If MS is so crappy, why aren't we all using OS/2?

I happen to believe that Microsoft's software development process is way better than Toyota's and as you wrote in your following post (with which I fully agree for the record ), the challenges are completely different so the comparison is a bit of a stretch. Ferchrissake, Toyota uses the waterfall model... they don't test anything until the coding is complete!!! If they missed something during the design phase or if someone has a good idea later on, oh well... bad luck I guess It may make it into the next generation 5 years later or something.

[Loren]

Originally Posted by BLH

In the automatic. The shift selector tells the ECU to change to neutral. Get the ECU confused enough and maybe it will not shift into neutral

I just looked at the service manual (since I don't own an automatic), and there is a physical shift cable from the shifter to the transmission. I don't think it's possible for the ECU to override you physically putting the transmission into neutral.

Interesting side notes:
You can uplug the electronic shift cable from the transmission and drive the car shifting manually using the shift lever. (this is listed as a test procedure to verify that a shift-related fault is electronic and not within the transmission itself)
The lock-up torque convertor only locks in 4th gear above 37 mph. (this is why people who accidentally drive around with the stick in 3 get such poor MPG)

It's amazing what you can learn by reading the manual.