Steering Power Low

Does anyone know if the tow could have been avoided by adding some fuel and recharging the 12V battery at the roadside?

 

Just adding fuel would likely be enough. I believe it has to be more than some threshold, say 3 gallons? Obviously if the 12 volt is run down it will need to be dealt with, but if you can jump the car or manage to start it, you should be ok to your destination.

 

Our resident Mr. Curious Guy, Bob Wilson, has intentionally run his various Prii out of fuel more than 50 times, as part of his numerous technical investigations. I don't recall him ever needing to recharge any batteries after merely running out of fuel. He just poured in the new fuel (always brought along for these tests), fired up, and drove on.

In fact, I'm now wondering why OP's 12V even ran down. Was it drained by leaving the car in a non-Ready accessory mode for too long after fuel starvation?

Something we know from other out-of-fuel members is: don't try to start the car / crank the engine too many times before adequate fuel is added. The car counts these futile start attempts, and locks out further attempts after a certain number (3 ??). (Maybe to save enough HV battery charge for a real start later?) The first victims had to be towed to a shop and pay for a Reset. Then subsequent victims learned that disconnecting the 12V long enough for the internal computers to forget, erasing their memory, was sufficient to achieve the same reset.

The best avoidance: don't get cocky about how far the car will go when the low fuel warnings are flashing. Over short distances and times, fuel consumption rates are much more variable than most people realize. It is easy to mess up, miscalculate, or run into worse-than-average conditions, and get caught short.