Can accessory mode be disabled?

Hey Priiheads - new owner of a used 2010 here, and for the life of me I cannot get the car into accessory mode. It should be simple, press the power button without your foot on the brake, right? but no... it just doesn't do anything.

But here's the thing - the car is a former rental (Zipcar), and I wonder if they somehow disabled accessory mode to avoid dead-battery issues?

The other (less appealing) possibility is that they broke it accidentally somehow while wiring up their magical gizmo that allowed Zipcard holders into the car with no key... but that doesn't make as much sense to me.

Any ideas?

 

Thanks for the replies guys, but (at risk of sounding like an A-hole here) it seems like you didn't read too closely.

I know how it's supposed to work... and I even dug out the manual to confirm yesterday, but it just... doesn't. One press, two press; press quickly, press slowly; press "firmly"; hold the button... none of the possible actions I could come up with related to pressing the power button without pressing the brake caused anything noticeable to happen.
It should have some kind of feedback, right? The manual implies some kind of light on the dash when in ACC mode, but I even tried turning on the radio "blind" after pushing the button, and nada.

So... is it possible accessory mode may have been disabled? I guess I could ask a dealer, but I wouldn't have much faith in the accuracy of the answer.

Also... I presume you're exaggerating about the whole "seconds" thing? I know the 12v battery is smallish, but it should be able to run the radio for a decent stretch if it's in good condition.

In this specific case I wanted to let my wife listen to the radio while waiting in the car for 10 minutes, and was annoyed to see that the traction battery lost 2 bars while sitting in "ready" during that time.

Overall a small issue but annoying nonetheless... of course probably less annoying than having to get the car jumped due to a dead battery.

All that's required of the 12v battery is to boot the ECUs, right? Any specs on how many amps/watts that takes? "Seems like" it shouldn't be a lot.

 

I don't have any info on the 12v battery condition. I understand there's some way to test it via software?

45k miles.

One update - I heard from the broker that I bought the car from. He bought a 2nd Prius from the same source, and it has the same no-acc issue. I guess this doesn't tell me what the cause is, but at least I'm not alone.

 

She was sitting with the radio on.

The point is that most of the power is being used (from the traction battery) keeping the car in "ready"... which is what I'm trying to avoid by putting it in Accessory mode. Except it doesn't work.