SuperAkuma

2006 RX400h with about 230k

I don't own his car but helping a friend with this issue. He said he had issue with the car loosing power or just turning off while driving. I am not too familiar with the Lexus hybrid system but I scanned the car and P0A05 came up. It also has a check VSC and check hybrid system on the dash as an error. I did a little research and everything pointed to the invertor water pump not working or the fuse to it. The fused checked out to be fine. I checked the connections and cleaned it. I have a high level scan tool that is able to activate that water pump on my scan tool. When I turned it on, the coolant on the invertor pump started to move like it was being sucked or something. I put my hand on the pump and you can feel the pump action.

I am a garage mechanic, I've worked on mostly older honda/toyota/subaru but I am not too familiar with this. What other things should I look at or inspect?

LeX2K

Failed inverter pump is fairly common on this platform I would simply replace it. Can test okay but fail as you drive. You may also get code P0A93. Replacing this is easy enough only a couple of hoses, grab a jug of Toyota Super Long Life coolant and top off the reservoir. There is a bleed procedure but I find the system takes care of itself. Here is the pump.

https://parts.belllexusnorthscottsda...040-48080.html

789

Check starter battery if all else looks ok. had check hybrid and vsc warning lights that came on more and more regularly without explanation as everything checked and working. The starter battery appeared ok was starting ok but was 5 yrs and v slightly down on power…changed it and immediately faults came on less frequently and by end of a few days no faults and none since as if the system reset itself.

SuperAkuma

The regular 12v battery was replaced last year there is a 2023 sticker on it.

[​​​​QUOTE=789;11761910]Check starter battery if all else looks ok. had check hybrid and vsc warning lights that came on more and more regularly without explanation as everything checked and working. The starter battery appeared ok was starting ok but was 5 yrs and v slightly down on power…changed it and immediately faults came on less frequently and by end of a few days no faults and none since as if the system reset itself.[/QUOTE]