Originally Posted by bobdole888
That's an interesting thought. I don't know how the car would know it's still moving when all wheels are locked... I don't have GPS.
That's pretty much it right there.
The following is an oversimplified explanation but here goes: ABS works by calculating the wheel rotation between all 4 wheels. If during braking, some of the wheels stop while others are still turning, the computer realizes that those wheels have locked up and it engages the ABS on the wheels that have stopped.
However, if all 4 wheels stop rotating at the same time, (for example, what could happen when braking on ice at low speed) then the ABS system assumes the car stopped and thus, doesn't engage the ABS.
In any case, sorry you got in a fender bender. I had almost the same thing happen to me a few years ago in my FJ Cruiser. Really bad tires + ice = a bad time.