elusive stage 4

I face that situation every day. I agree, it's the most frustrating thing.

Like you say, one option is to leave a little gap, then run up over 34 mph, and glide long enough for shutoff, but that's not always possible.

I have found though, that you don't have to be at a complete stop to get it to cut off. If I glide at 3 mph or less for the 5 seconds or so, it will shut down and I can manage that easier than a 5+ second complete stop. It also conserves a bit of momentum for when you ease back into electric so you don't risk cutting the ICE back on. (Actually, I think it's probably really 4 kph, the car seems calibrated for kph on the transitions, which doesn't always map exactly to mph. I aslo see the kph thresholds on the regen/mechanical brake transition and the '42 mph' engine cut-on). The key though seems to be that you HAVE to be gliding the entire time (no arrows at all on the display).

The other thing that really does work for me is the B-N-D stop. If I drop it into B just before stopping then cycle through N-D with the slightest pause at N, it shuts down immediately, and will stay in electric until you push the pedal too hard again. Elapsed stop time is about one second instead of the interminable wait.

 

Hobbit, when I saw your naked prius 'people's choice' at the AltWheels festival, I hadn't yet taken delivery of mine- and I hadn't yet found this forum. I didn't know what a CAN bus scanner was and I don't remember seeing anything that might have been one, in retrospect.
So, do you have a SCANGauge or CAN-View?
I'd seen mention of stage-4 operation but I hadn't gotten around to finding this article - thanks for the link. I'll have to pay more attention to see if I can see the transitions reflected in CAN-View data...

 

The only possible explanation I can see is that it's a calibration step. It wants to measure some characteristics of the engine's running and/or shut-down when up to temperature - and waiting until you've stopped is the only way to do it in controlled conditions.

 

My car seems to get to stage 4 somehow quite regularly without ever stopping, but not always. I have not been able to figure out how, but there seems to be some other way it can get to stage 4.

This happens even more now since the SSC50P update. I start wondering where I can stop to get to stage 4 and discover I am already running on battery.

 

I do see this effect, but then later it seems like stage 4, still without any stops.
My usual commute I get to full warm up on the highway going 55. As I come off the ramp my car gets under 30 mph and I am on battery. Some days I can stay on battery for a couple of miles.
If engine comes on, it will stay on a while as you describe, but then later it goes off again, and still no stops.

And other days when I do make a full stop it doesn't work that differently. Sometimes it goes to battery easily, other times the engine seems to run for no reason. Overall though I am still getting much more battery mode operation on my commute than before, espec on days

Below 32 battery temp the engine runs, but at 35 to 50 deg I get battery operation like I used to only get when temps were over 50.

One route example is 128 to rt 38 north to Eames St. Some days I can go on battery almost all the way from the off ramp to Eames, with maybe one engine run for one of the uphill parts.

So I guess I'm not sure how to tell when I am really in stage 4 any more. I do notice if I am slowing down and engien goes off it does not lock in stage 4 even if I make a full stop at a light. I need to stop again some days so the engine goes off while I am stopped.

 

Hobbit,

I saw your question and some responses over on yahoo! And been trying to figure out what my car actually is doing.

Today I went off with no block heat warm up and went down 128 to 93 and then off to Commerce Way exit so about 2 to 3 miles between ramps!

Car was stopped at lights before I got on 128 but well before warm up. Engine stayed on.

For both exit ramps the car went into stealth immediately when I slowed below 40 mph.
And I never stopped or slowed below 25 mph.

So since it did it twice in a row does this mean stage 4? Or maybe it doesn't count because I went over 42 mph in between?

Then for other times the car clearly gets to stage 4 easily without stops etc, if the car is already warm because I stopped somewhere for a short time. So I am thinking maybe this applies to my car in the mornings too, when warmed up with my block heater? So maybe the car being warm at start up fools the car into skipping the idle calibration step?

I will start watching to see if I really get to stage 4 for other cases where I am going under 40 and have not prewarmed with block heater. Maybe for these I do have to stop, often twice, since the first time the engine may go off before I get to a stop.

 

I would suggest that the referenced article represents some of the primary parameters for entering the each of the stages. A couple of things to note. The information sited was largely gathered in Japan with Classic Prii. I would suggest my 04 never followed those rules all the time. That is based on observing the cars behavior, using the MFD Energy Screen but not trusting it and later using the ScanGage to get more information. The problem with the ScanGage data is the considerable delay in updating the data (several seconds).
There are clearly other parameters that are being considered when the systems determine that you can achieve ICE off in Stage 4. Battery SOC is clearly one of them. Once I got the CAN View it seemed to confirm that. I would purposely stop at one stop sign I had early in my commute. This would let me test the 5 sec ICE off rule. I appear to be in Stage 4 ( on warmer days? not yet sure on that one yet) with out a 5 second stop but not always. I also find there are times when after fulfilling all the criteria for Stage 4 operation I can not get the car in to glide (low stealth) mode no matter how hard I try with out resorting to the EV or N option.
I also think this now happens much more often and easily since I have had the SSC50P reprogram. The car goes to ICE off much more easily including skipping over the 5 second requirement to get to apparent Stage 4. The only caveat to all of this is that I use a block heater and radiator blocker in an already mild climate and that makes a big differencee. I am usually in stage 2 shortly out of the drive way and over 70 C 158 F by the time I get to that second stop sign.

 

I would suggest that the referenced article represents some of the primary parameters for entering the each of the stages. A couple of things to note. The information sited was largely gathered in Japan with Classic Prii. I would suggest my 04 never followed those rules all the time. That is based on observing the cars behavior, using the MFD Energy Screen but not trusting it and later using the ScanGage to get more information. The problem with the ScanGage data is the considerable delay in updating the data (several seconds).
There are clearly other parameters that are being considered when the systems determine that you can achieve ICE off in Stage 4. Battery SOC is clearly one of them. Once I got the CAN View it seemed to confirm that. I would purposely stop at one stop sign I had early in my commute. This would let me test the 5 sec ICE off rule. I appear to be in Stage 4 ( on warmer days? not yet sure on that one yet) with out a 5 second stop but not always. I also find there are times when after fulfilling all the criteria for Stage 4 operation I can not get the car in to glide (low stealth) mode no matter how hard I try with out resorting to the EV or N option.
I also think this now happens much more often and easily since I have had the SSC50P reprogram. The car goes to ICE off much more easily including skipping over the 5 second requirement to get to apparent Stage 4. The only caveat to all of this is that I use a block heater and radiator blocker in an already mild climate and that makes a big differencee. I am usually in stage 2 shortly out of the drive way and over 70 C 158 F by the time I get to that second stop sign.