Accelerate S3 to S4?

<div class='quotetop'>QUOTE(ScottY @ Sep 7 2006, 09:11 PM) [snapback]316097[/snapback]</div>

Stage 3 and stage 4 are all about engine temperature. After being on the highway that long, everything shoude be at temp for stage 4. The engine will run if the battery SOC is too low, could that be why it is staying on at the light?

 

I have the same problem. Once in a while it does get to stge 4 without me ever stopping, but I have no idea how.
Normally I try to time htings so I have to stop at at least one traffic light. Otherwise I pull over and park for the 10 seconds some days.

Some days I think it works without stopping because I stopped at a light during the early warm up part and it was able to calibrate the idle there.

Also I do sometimes use the EV button but rarely due to going over 32 mph. But when I do I push it on and off too, to simulate what the car would do in stage 4. Once you learn how the car acts you can match it pretty well and then not lose mileage.

 

<div class='quotetop'>QUOTE(ScottY @ Sep 8 2006, 11:11 AM) [snapback]316097[/snapback]</div>

AFAIK, there is none.
However, there is one way not to have the idling. Just cheat the coolant temp is always below 70 C.

Ken@Japan

 

both the Classic and the G2 do the same thing. When I first got the second Classic (2k3) I drove it for about 300 Km's from a cold start and then came to a stop at at a traffic light and after 6 seconds it went into S4 and the ICE stopped. The 2k4 I've driven it for about 6 Kms and not had to stop at any lights or stop signs and then get stopped and after about 6 seconds it goes into S4 and the ICE stops. From the start of that trip the ICE was at 48C when we left and it was in the high 70's to low 80's for most of it but didn't get stopped and it stayed in S3. As for spoofing the temp sender output, someone here on PC did it and it set the CEL.

 

How about if your driving on the freeway and you stop at a rest stop, for example, and shut down the car. When you restart it will go through stages 1 and 2 quickly because it will already be at operating temperature. But because you won't stop at all it will go from stage 3A to 3B and stay there until you slow down below 34 MPH again maybe 200 miles down the road. But does it matter? I understand that for speeds above 34 MPH stage 3B is the same as stage 4 anyway. Or is there some other way it gets into stage 4?

Edit: I think this is the same thing Frank H. just mentioned.

 

<div class='quotetop'>QUOTE(ScottY @ Sep 9 2006, 02:06 PM) [snapback]317018[/snapback]</div>

I have a 2005. I don't know how it gets to stage 4 sometimes. My speculation is that I do stop enough in an earlier stage at lights when engine is still too cool, and sometimes it calibrates there maybe. Most of the time I have to do the stop after it reaches about 163 degrees F.

I do go around a rotary when I get off the highway and it may be that even when I don't have to stop it gets me slow enough for the idle to calibrate sometimes. I do find that even at lights when I stop and yet not long enough for the engine to actually stop, say for 3 seconds, it turns out it gets to stage 4.

I think the terrain and how long you can coast down a hill affects it too and sometimes helps it into stage 4 without the stop.

 

<div class='quotetop'>QUOTE(ScottY @ Sep 10 2006, 03:06 AM) [snapback]317018[/snapback]</div>

Please refer to following schematics.
The left one is normal and the right one is modified for the coolant temp (THW) thermistor.
You can tell the normal temp to the engine ECU setting 0 ohm value of the variable resistance
When the coolant temp is going to exceed 70C, set the ohm value to 50-100 ohm.
You'll be staying in the S2 and the idling will never been occurred.

Ken@Japan

 

S3b to S4 is not *entirely* about ECT, as has already been more or
less stated. For some reason, the stationary idle-check dance is
still required even after you're well over 70 degC. Sometimes this
seems to be bypassed if you've restarted the car fairly soon after
a hot shutdown -- possibly it's if things power up and the system
sees it's already over 70 degC? Haven't tried to dope it out. In
the meantime, if you're stuck in S3 and traffic, about your only
option is to get handy with your EV switch until you get a long
enough stop to let the chicken-dance play itself out.
.
This *is* one of the more annoying and mileage-killing misfeatures
of the car's operation, hello toyota are you paying attention, this
would be a nice ECU reflash simple fix.
.
_H*

 

<div class='quotetop'>QUOTE(ScottY @ Sep 11 2006, 01:38 PM) [snapback]317598[/snapback]</div>

I've been using it for about a month, and no error has been reported.
It's neat I can let the ICE idle-checking anytime I want.

<div class='quotetop'>QUOTE(hobbit @ Sep 11 2006, 02:45 PM) [snapback]317613[/snapback]</div>

The feature is required by the system, therefore it exists.

Ken@Japan

 

I was the one originally spoofing the coolant temperature sensor; my original circuit was a bit different than ken's because I'm on a Classic and it doesn't have the same set of stages as the G2 Prius (specifically, there's no auto-stop at all below 70C). Whereas ken is adding subtle tweaks to the existing voltage, my circuit was basically completely overriding the actual temperature reading because in my case, I wanted the ECUs to think that the engine had reached 70C so that the Classic engine management algorithm would auto-stop.

In my case, the first time I tried, it, I figured out what voltage was required for a reading of 70C and basically chose a resistor set to that value, and then started the car.. The engine ran for 10 seconds then promptly shut off and displayed the MIL and codes for P3101 and P3191 if i recall.. Once the cat has warmed up normally (ie, if you drive the car for 10 minutes first and then turn it off), you can spoof any value you want and the engine really doesn't care, but when it's cold, it's not happy if you lie to it... Alternately, if you can get on the road and drive for about a kilometer without stopping, as soon as you're moving, you can crank up the temperature reading and when you come to a stop, the engine will also stop, even though the actual coolant temp may still be well below 50C..

What I'm doing now, is starting at no spoofing, allowing the engine to warm up slightly and establish idle, then I rapidly ramp up to 50C, which turns off the "cold temp" light and switches the VVT-i out of the low-power "warm-up mode", and then I ramp up to 70C based on vehicle movement and hold there until the actual temperature exceeds 70C at which time the circuit is switched out.. I've got a little microprocessor to monitor and control everything, but I'm still tweaking and and tuning the algorithm... Before ECT spoofing, my usual 1st 5 minute consumption bar was always between 7.5 L/100km to 10 (infinite) L/100km; with the spoofing, 7.5L/100km is the maximum consumption; depending on whether I have to wait at an intersection or whether I can just get going, I can get as low as my regular consumption of 4.8 L/100km on the first 5 minutes.. This applies even in the winter and was the difference between a usual winter consumption of 5.6L/100k or worse and the 5.2L/100km I achieved this past winter..

Again, this is on a Classic, which doesn't have the same operational modes as the G2, so what I'm doing is probably not ideal for the G2, and ken's solution may actually be a better choice (and should never trigger a MIL either)

 

<div class='quotetop'>QUOTE(ScottY @ Sep 11 2006, 11:09 PM) [snapback]317665[/snapback]</div>

I believe the Coastal Tech EV mod makes the 2 second delay.
Japanese factory EV switch works instantly. I think other switch mods, including high-beam flasher, work instantly too.

I've heard the reason is something to adjust the idling rpm to meet the current contamination of the throttle body.
I'm not removing the "feature", just to delay the timing I like.

Ken@Japan

 

<div class='quotetop'>QUOTE(ScottY @ Sep 11 2006, 11:50 PM) [snapback]317689[/snapback]</div>

Me neither. :blink:

You have to join the http://techinfo.toyota.com/ site.
Anyway, The THW signal is located at E4-19.

Ken@Japan

 

And not carefully the weird ordering of the connectors down the
ECM -- 4,5,7,6 ... that's NOT a typo.
.
_H*