2004 Toyota Prius DTC codes P0A40, P0A41, U0100, U0111

After a short trip, returning home is usually a welcome and pleasant time.  However on getting home and finding my Prius dash lit up like a Christmas tree with master warning and hybrid system warning lights, my enthusiasm quickly faded...

The last time this happened a rambunctious squirrel had its way with a the motor generator position sensor (generator resolver), as evidenced by some bare copper strands swaying in the breeze when looking straight down the front of the engine behind the radiator.  I suspected something similar, but this was a little harder to find.

After getting the car up on ramps, and crawling underneath, I finally found the offending connector, the motor position sensor (motor resolver), conveniently located halfway up the engine behind the drivers side wheel well.  I already had the Toyota part number and the tool I needed from the last time (made from a precision hex driver and a grinding wheel), so I ordered another 10 pack for about $7 each.

After removing the driver's side splash pan (have extra plastic body fasteners on hand!), I was able to get one hand in through the wheel well and another up underneath to wiggle both the motor temperature sensor and resolver plugs free.  The little rascals had chewed clean through two wires and nicked a third, but for the life of me couldn't remember how to get those darn terminals out.  After nearly an hour of unpleasant language, I conceded to cut the entire plug off (I had six new terminals and splices, well 10 actually).  After working at the kitchen table for almost another hour (dinner anyone?), here's the trick for my ailing short term memory and all you others that need to do it....

    

...remove the white plastic locking ring FIRST!!!  With a gentle pry up on both short edges of the white locking ring (exposed at the edge of the central plug), it pulls up and completely off the plug, exposing the plastic catches that you need to move away from the terminal to pull them out the back.

I'm waiting for the rain to subside so I can put it back on and DRIVE my Prius off the ramps.

End note, the U codes from the scan tool have to do with CAN bus communication to the battery, I think these are incidental to the furry friend incident, as they could be cleared from scan tool.