Sometimes, when I'm zooming up the motorway, I get the triangle and techstream throws up p0824. When I'm round the town again, I cancel it and it stays off. I've looked at the fan and it's clean and there doesn't appear to be any corrosion on the wires so I thought I'd test the speeds in techstream: It runs ok on No 1 but as I advance it, the triangle pops up. it's as if it's not keen on running at the higher speeds. What makes it run faster and slower?
What did you use to get that code? Just asking because it does not appear to be a valid Prius Gen 2 code. Is it perhaps a mistyping of P0A84?
So, the HV battery ecu controls what the blower does. The ecu turns a relay on or off that supplies 14V to the (+) side of the blower. Then the ecu sends a variable squarewave signal (Pulse Width Modulated) to the blower controller- in essence a transistor that can adjust how much the (-) side of the blower is connected to ground. The ecu monitors that (-) circuit. When the blower is off there should be 14V on (-), at 50% on there should be 7V, at 100% on there should be near 0V, etc. That code indicates that the battery ecu saw a lower voltage on that (-) side monitor circuit (labeled VM on the diagram) than it expected. You should get a copy of the service manual with diagrams so you can start testing circuits with a multimeter. I might start by confirming that the (+) side stays at a steady 14V when controlling the blower with techstream. Posted via the PriusChat mobile app.
Thanks for that. I've put the wiring diagrams for gen 2 in the file library now for anyone that wants it.
