Toyotas failure

The following is from the repair manual (bold/italics mine):

When the auxiliary battery is replaced or the cable is disconnected from its negative (-) battery terminal, the ISC (Idle Speed Control) learning value will be initialized and symptoms as a noise from the hybrid vehicle transaxle assembly may occur until ISC learning is performed.

 

Thanks, that seems to explain what I observed.

 

What if there are two regular drivers of a Prius? My wife and I drive very differently (e.g. she hotdogs to red lights, I coast in; she gets 45 mpg, I get 55). Are we creating a schizophrenic Prius computer?!?!

 

Good question and I think the answer is a big no. The car adapts to things such as altitude, temperature, octane of the fuel, etc. It adjusts ignition timing, fuel mixture, injector timing and a few other parameters.

It doesn't even know about the difference in drivers and couldn't adjust for that anyway. All drivers will occasionally need full throttle, all drivers will drive on the freeway, and all drivers will chug around town. The car needs to be ready to meet the demands of any driver at any time to the best of its ability rather that be maximum acceleration to enter the freeway or going for maximum mileage.

 

tumbleweed gave an accurate answer. However, (humor only), you might be onto the true cause of all the unintended acceleration events......