What is the idle check ceremony?

Prius checking if engine is still there and responding to commands? I don't know.

 

never heard of it, but that doesn't mean anything.

 

It's in S3, right here: Gen3 warming up stages | PriusChat

I think this is where the car calibrates the O2 sensor. It can't do this while the car is cold.

 

I've always figured that the idling check ceremony is a combination of a bad translation from Japanese plus carrying a concept over from the 2nd gen that doesn't really exist on the 3rd: Hit 70°C, and the engine will turn off when you're off the accelerator. I don't really see much of a "ceremony", or anything else that's particularly different. As far as I'm concerned, S3 doesn't exist at all, at least as described.

What does exist, as I've noticed, is that after reaching 68°C, the car is much more amenable to shutting the engine off during a glide; it can be done with almost 100% success. Before hitting that point, I'd say the success rate is probably ~50% or so for any given attempt to glide.

 

I imagine after that point the mixture is leaned and the timing advances... since that cat and coolant is warmed.

 

It's needed to adjust the amount of fuel injected so the fuel/air mixture is correct. I think they've been around in the US since the 80's or so, but I don't have a source for that: I'm just going from memory.

 

Ceremony ensures super wonderful good time!

 

At least the early 80s. My '81 Olds had one. I believe the Prius has two, one before the cat and one after it.

 

looks like the O2 sensor has been in some cars since the late 70's.
Oxygen sensor - Wikipedia, the free encyclopedia
By measuring exhaust gases, you can perfect the fuel/air mixture. The Prius measures before and after the catalytic converter.

The idle check is much less a problem in Gen 3 than in Gen 2.

 

Um.. all modern cars have O2 sensors..
There is definately a difference in s3 and s4..
The idle check ceremony has something to o with the car seeing what conditions the catalyst is iin. Emissions is king and if the car isn't at peak operating temperature then the engine will continue to use fuel while gliding. The difference is thst under 46 you can still do a zero fuel glide even in s3.
You have to be in s4. to get full warp stealth at interstate speeds.
HUGE difference.

 

Re: the "idle check ceremony", we'd asked the Chief Engineer of the Gen 3 at the Gen 3 unveiling in January 2009 about what the deal was. See Update on my prius... | PriusChat and I'm confused about S4 mode ???????? | PriusChat.

We'd just seen the Gen 3 for the first time (months before they went on sale in ~May 09) that evening.

 

So, basically, you are saying that no one knows?

 

From what I'd heard, the answer was sensor calibration.

 

The good news is this control law no longer exists in the current Prius. The description is a left over from the NHW11 and NHW20 last sold new in 2009.

It is an ambiguous Japanese-English artifact:

• "idle check ceremony" - original description
• "idle check protocol" - more English-like translation

In the earlier model Prius, the engine would at speeds under 34 mph continue to run until it passed the "idle check:"

1. engine coolant at or above 70C
2. car stopped for ~10-15 seconds

We still commute using our 2003 Prius so I'm partial to routes that have a stop where I can trigger this test, this protocol, to occur. Sometimes, I'll stop at a light and knowing the car has not yet gone through this mode, I'll hold the brake and pulse the accelerator to get the engine spinning. Within 10-15 seconds, the engine will auto-shutdown and the car is in full 'hybrid mode.'

Bob Wilson

 

O2 Sensor also call it as lamda sensor.Toyota Prius has two lamda sensors with advance E.G.R. mechanism( Exhaust Gas Recirculation)These two sensors are situated after and before of the catalytic converter.It measures catalytic converter doing it's job.Reduction of harmful gases by measuring input valve and output value."three-way catalytic
converter introduced in 1975 typically it needs a lamda sensor.

 

I have noticed that when I go on a longer trip and then stop at 170F or more for a short stop, then after turning the car on (the SGII still reports temp around 170F), I find the engine doesn't want to stop during glides. It takes a few minutes of engine running yet, a time or two, for it to want to turn off during glides. Whereas according to the Warmup Stages sticky, I should be in S4 if I switch the car on above 140F...

 

Are you in ECO when this occurs?