MFD shows incorrect engine status

While this is a totally normal, I'm not sure it is actually inaccurate. The engine is running, sure, but do we know that energy is flowing from it during that state? The screen alleges to show energy flow not ICE state. You could also add a tachometer, or do one of Hobbit's many mods.

 

The MFD does not show engine status; it shows power flow. The engine can run without power flowing to the battery or wheels.

Tom

 

In this case the engine is probably running to finish heating itself or the catalytic converter to optimal operating temperature. The battery is evidently already at its optimal state of charge at that time, so further charging would reduce its lifetime by some trifle. If the engine is running anyway one might as well drive the car at that time, to get some useful work out of it.

 

I obviously do not designed the prius. but base on my observation. I think when engine is on while there is no energy flow. that usually mean that the computer of prius detect that the engine is not hot enough and need to run the engine to make sure it reach the normal operating temperature. This piece of energy is waste. So this will happen more often in winner then in summer. of course this also mean that you are burning gas. and therefore, mpg will slowly reduce.

 

Here is something that may be an error. When I drive in that sweet spot, no arrows, and watch my SG2 the battery SOC goes down some. This tells me battery power is being used but it shouldn't be when there are no arrows showing.

 

Yes, I've seen many times where I am stopped for a red light, the engine is not running, the car is not moving, but I see an energy flow (arrow) running from the battery to the wheels. This usually happens when the car had been warming up the catalytic converter before ICE shutdown. I know the engine is not running because I experience the "shudder" when the ICE sheds its momentum and stops.
I suspect that it's actually showing energy running to something else from the traction battery, but I have no idea what is really happening.
Initially I thought the car was heating up the catalytic converter electrically, but I now know this doesn't happen (but I think it might be a good idea...)

 

I have learned that when you are in stealth with no arrows you still are using a little battery energy. How much exactly I dont know but it is some.

 

Not an error, just the way it's designed. It's not a precision device.

However, you are correct that there is current flow out of the battery during a sub-41 MPH no-arrows condition -- a "glide" as most of us regulars in these parts call it. There appears to be a more-or-less linear relationship between current flow (up to 8 amps) and vehicle speed when using go-pedal feathering. On the other hand, using neutral to glide uses considerably less current and maintains SOC longer, though at the price of slightly increased drag. See this for more.

 

yes, when the car is not moving and you step on the brake. there is an arrow from the battery to the motor. that is normal. because it is powering the motor. why is that, because you did not step on the brake hard enough. do two tests, when you see this happen next time, either hit the "park" button or hit the brake harder. that will deactivate the power from battery to the motor. it is just like regular car when you stop at "D", the engine try to move the car but your brake try to stop the car. prius try to simulate this by activate and deactivate the motor at the position of the brake that you step on.

 

The cartoon only shows energy flows within the drive system. Energy flow out of the battery to the A/C, lights, accessories, etc. is not shown.