is a special fault code machine needed for hybrids

The short answer is yes. The Prius has several ECU's that control the hybrid system that standard code readers cannot communicate with. You need a Prius specific scanner to read the proper codes.

Some Advance Auto and Auto Zone's can read the Prius specific codes for you. Of course the dealers have the Techstream software made for the Prius.

 

Welcome to Prius Chat!

Ask the seller if you can take the car to a Toyota dealer of your choice and pay them to pull the codes and do a courtesy inspection. While they are looking at it, they can check the traction battery and other items. As said above, Generic code readers don't always pick up all of the Prius codes, plus sometimes they can misdiagnose (give wrong code). Techstream is the best (Toyota dealers). There is another code reader you can use on a laptop, but I can't recall what the name of it is.

 

Just to add to the above, the difference is not strictly hybrid vs. nonhybrid, but just that the Prius has so many proprietary ECU's compared to other cars. I am not sure as to the root cause of the false positives returned by some generic readers, but it may have to do with the bus protocols or bus speed used in the Prius, as necessitated by all that extra traffic.

The list of Prius capable readers includes: The Torque app for Android phones, ScanGaugeII, and the miniVCI (eBay). Autoenginuity has not proved reliable for some PC'ers, but hopefully is improved by now (?). The cost of going to Toyota just for a scan makes ownership of one of these options more than worthwhile. Such is the current era's equivalent of opening the hood and checking the oil. (Which Prius owners need to do as well!)