Engine charge for HV Battery not working properly.

you have to hook up a scanner for trouble codes, but i think you would get a dash warning lite if there were any codes to scan. some auto parts places will scan it for free.

 

Have you cleaned the MAF sensor as in my post (13) this could make a difference, also did you check the vacuum hoses to the PCV valve and any other vacuum hoses on the system. Check for leeks where the manifold fastens to the cylinder head.

I believe your lack of charge at what would normally be tick over is caused by the hunting "the engine ECU trying to establish control of engine speed until it does this it cannot set a speed to turn MG1 to charge the HV battery.

When the engine is cold the speed is set higher and the mixture richer so that a small air leak makes little difference.

If there is an air leek after the MAF there is no accurate measure of air flow into the engine. Revs will rise and the exhaust gas sensors will try to bring the mixture back to normal the ECU will then bring the revs down by shutting the throttle almost stalling the engine so it will open it again causing the hunting effect.

 

Just to answer your concern about Neutral, if the ICE is running when switched to Neutral it will coninue to run. If the ICE was off, it will remain off. This is normal.

 

I'm wondering if you disconnected the battery (12V) while cleaning the throttle body? After reading the previous posts the next thing I would do is disconnect the 12V battery for around five minutes. This will make the ECUs relearn their adaptive settings. If that didn't work I would then put it in service mode and check the fuel trims with a scanner. As far as vacuum leaks go, I chase them down all the time, however, never on a Prius. Also, Prii do not have most of the stuff that commonly leak.

 

Thanks I had not thought of resseting the ECU's.