Issue After Replacing Inverter Coolant Pump

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ethompson20, Mar 24, 2025.

  1. ethompson20

    ethompson20 New Member

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    Hey guys, a little help here.

    07 Prius 289k miles

    Got the red triangle of death for the second time. Last time I took it to the shop and they replaced the inverter coolant pump, that was 50k miles ago

    Saw how often those pumps fail. Checked the reservoir, sure enough no turbulence. Went ahead and replaced the pump myself. I can hear the pump running now and feel it vibrating...but still no turbulence! I can get coolant from the bleeder valve. Fuse looked fine. Bad pump? Big air bubble in the pump? Any help figuring out my next move would be appreciated.
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Usually when you change this thing and you put the hoses back up connect everything up and your low on coolant You fill up the reservoir and then you ready the car get out stand in front of the inverter and look at listen to the pump You hear it sucking air and then all of a sudden it'll fill with water The noise will drop dramatically as will the level in the container No need to open the bleed screw when the level drops in the container fill it watch it a second It should level off and you should almost not hear the pump running at all turbulence is moot It should be almost non-existent I mean you really have to be looking in there maybe even with a light It is very faint this pump barely moves water or coolant It has to move the coolant so slow that it dwells in the core of the radiator so that the heat can be wicked away by the fan or forced air coming in the front of the car so there's no need for it to be whizzing around through the reservoir at 40 miles an hour more like about a half a mile an hour barely able to see that's correct so what are you saying You getting a code you still got the red light on the MFD the AM2 fuse is blown The pump is running you verify that with your hand on it If you squeeze the hoses going to the inverter pump You should hear the pump labor when you squeeze the hose that seems like everything is fine go for a drive and see what happens nothing's going to happen if it overheats a little overheat it'll get a little warm and you'll come home are you using fake pumps?
     
  3. MAX2

    MAX2 Senior Member

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    The pump may not work due to its own malfunction or when there is no power supply to it.
    Have you checked the power supply and the fuse?