I have a question about Generation 3 ( 2010 until 2015) ABS actuators... When ordering a NEW Actuator, is it essential to get the EXACT same part number as what is in the vehicle or are ALL the Actuators that are used in the Gen 3 Prius interchangeable? I don't see any information online that would cause me to believe that I must use the same part number. Conversely, if there is a hardware or software upgrade or something else that will cause one model to NOT work with the existing car, it is NOT visible from the exterior of the part. They all look exactly the same from the outside. Does anyone have any info on this? TIA!
Out of the box, they are not interchangeable. There is some evidence that the skid control ECU (which is within the ABS actuator assembly) must be matched to the power steering ECU on the vehicle. Essentially, the part that you need to install must either have the same part number as the one that came with the vehicle, or be its supersession. It has also been speculated that the two variants (for the hatchback, not the wagon) differ only in the factory flashed calibrations. If this is true, one might be able to get by by installing the "incorrect" variant and subsequently flashing the "correct" calibration. I am not aware of anybody having tried this, but if you do, do let us know how it went.
It's possible that the calibrations mainly differ because of the wheel sizes. That's how the actuators are listed on parts.toyota.com, one for the 15-inch wheel cars and one for the 17-inchers. As it happens, those cars also got different power steering systems. The 17-inchers get a brushless three-phase assist motor with a resolver (like a tiny version of the MGs in the transmission!) and of course a completely different steering ECU for driving it. So it seems wheel sizes, skid ECU calibrations, and steering ECUs should normally all be in one group or all in the other. Interesting that you found the brushless steering motor is used on all Mexico packages. Do they then get the same skid ECU calibration regardless of wheel size, or have they still got different calibrations (which might be different from the US ones) for different wheel sizes? The repair manual info for C1203 indicates that the skid ECU likes to compare IDs with the body ECU, the power management control ECU, and the yaw and acceleration sensor. It sets the C1203 code if it doesn't like the answers it gets. Doesn't mention checking the steering ECU or the angle sensor though.
On the Toyota parts site, only the listing for 47050-47150 (the ECU associated with the 17" wheels in the US) even mentions the Mexico spec. Interestingly, the only tire size mentioned for the Mexico spec is 15", so it looks like all Mexico models do indeed get the -47150 skid control ECU, despite having 15" wheels.
