Toyota Prius Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
Why does the engine come on when there is no apparent need for power. I noticed this a few days ago. I had the windows down, I was next to a wall, and I could hear it running but the touch screen did not show that it was running.

I have also noticed that this happens many times when I first start the car. But this also happens when the engine is already warmed up and I am coasting, stopped, barely moving in what should be stealth mode, etc.

It also occurs that the engine will be off and the screen will show that it is on.
 

·
Registered
Joined
·
7,161 Posts
If the engine is truely warmed up and you are at a stop (car not moving), ICE should not start unless the battery SOC gets down to 2 bars.

During the warmup, the ICE is more likely to run when the car is moving, and more resistant to stop when the car is at a standstill.
 

·
Registered
Joined
·
466 Posts
flarend said:
Why does the engine come on when there is no apparent need for power. I noticed this a few days ago. I had the windows down, I was next to a wall, and I could hear it running but the touch screen did not show that it was running.
The MFD is an energy screen, not engine status screen.
It shows when the engine supplies some energy.
I have also noticed that this happens many times when I first start the car. But this also happens when the engine is already warmed up and I am coasting, stopped, barely moving in what should be stealth mode, etc.
You were at S3a of warming up stages.
http://priuschat.com/forums/kb.php?mode=article&k=14
It also occurs that the engine will be off and the screen will show that it is on.
I've never seen such.

[email protected]
 

·
Registered
Joined
·
1,434 Posts
Let me say that although hyperion is, in general, correct that the ICE will spin for any number of reasons and isn't consistently displayed on the Energy screen unless it's actually burning a measurable amount of fuel, that I disagree with his estimates of run-time percentage.

For instance. During highway driving or any constant speed driving over 41mph the ICE is spinning 100% of the time. During very slow speed/high traffic conditions it may run only 20-30% of the time.

On my usual commute it probably runs somewhere around 30-40% of the time. I have CAN-View and can and do monitor it as I work for maximum fuel economy.

Just realize that much of the time that you can tell it's spinning but you're not going anywhere that either it is burning miniscule amounts of fuel, or it's actually burning no fuel at all, but is being spun by MG1 in anticipation of restarting.
 

·
Registered
Joined
·
198 Posts
I'm sure Hyperion's 85% was not a measured number. Here is a table to translate the general use of percentages:

110% - always, and then some more...
100% - always
99.99% - always, but our lawyer won't let us say 100%
85% - runs alot, more than you'd think
50% - maybe, or maybe not
0.001% - never, but our lawyer won't let us say 0%
0% - never
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top