Hi folks, As a person associated with computers I am familiar with their tendancies to do the unexpected, sometimes from a program bug and other times from external interferences. (e.g. RFI) I ask the following: The only direct physical control we have over the Prius is brakes and steering - do the important ECU systems have built in redundancies? - in other words some duplication of control to allow for failures. Hyperthetical: What happens if the ECU misreads the throttle input as "maximum" - can the car take off out of control? There is no way to turn off the system except at low speed - I believe the Power switch is inhibited at normal speeds . Does anyone here have the technical info re the computer/s design? Aircraft "fly-by-wire" systems have heavy redundancy built in, with most triplicated and some 5 times - extreme example of course. Regards, kenmac
I can only offer a few points. 1) The brakes, which are electrically pumped, have a backup power store in the form of a capacitor pack in case the HV circuit fails. 2) If the throttle input jammed, you could switch to Neutral. I suspect pressing the brake would also override the throttle input - they're both feeding into the same ECU (anyone want to try that?). 3) The power button can be held down for a few seconds to force a shut-off (much like an ATX PC).
Yes, the Power button can be pressed for >3 seconds to shutdown - assuming the problem computer is not part of the shutdown process of course - the program may have crashed! If the power off function is completely independant (e.g. hardware driven) all should be OK. Anyway, as they say " it may never happen". kenmac
i am sure there are redundency measures in the system, as anthing otherwise would be suicide for the car company. On the software point, sure there are bugs, but a system as important as the brake and throttle control is tested over and over again until there are NO bugs. Also, ECU's don't operate on a window's paltform so we can be relieved somewhat.
If the system is forced to shutdown by a prolonged power button press, does the parking gear lockup engage like during a normal power off? That could be pretty catastrophic to lock the tranny at 50 MPH.
oh my god? can you imagine?? you would have to pull over after every few hours and reboot the car!!?? wonder how many other bad jokes can be made here...
