Can I run with ECT Power mode continuosly?
So I been giving it some thought and here is what I believe is going on.
Keep in mind these are just my opinions and not backed by any documentation or statistically relevant data.
When you hit the button to set ECT PWR mode on
This is what does not happen:
1. The throttle map is not changed. It does not open more compared to Normal
This is what is happening:
1. The timing is retarted. This results in a good low rpm power band, but in higher revs it actually suffers. Which is why the 0-60 times are better in Normal mode. This also results in an engine that responds quicker to the throttle input due to the retarted timing.
2. The gears hold on much more longer when you take your foot off the gas pedal, before actually shifting down.
3. The transmission also downshifts as much as 2 down, much quickly if the gas pedal is pushed in fast.
4. The transmission shifts down fast enough to keep pace with your slow down when you are braking. This is because they are anticipating the driver to push the gas pedal again, and when he does, it does not have to waste time in shifting down.
If you disagree with it, I have no problems. Just do not start pointing out that I have no "documentation" or proof to back this up. I do not.
Keep in mind these are just my opinions and not backed by any documentation or statistically relevant data.
When you hit the button to set ECT PWR mode on
This is what does not happen:
1. The throttle map is not changed. It does not open more compared to Normal
This is what is happening:
1. The timing is retarted. This results in a good low rpm power band, but in higher revs it actually suffers. Which is why the 0-60 times are better in Normal mode. This also results in an engine that responds quicker to the throttle input due to the retarted timing.
2. The gears hold on much more longer when you take your foot off the gas pedal, before actually shifting down.
3. The transmission also downshifts as much as 2 down, much quickly if the gas pedal is pushed in fast.
4. The transmission shifts down fast enough to keep pace with your slow down when you are braking. This is because they are anticipating the driver to push the gas pedal again, and when he does, it does not have to waste time in shifting down.
If you disagree with it, I have no problems. Just do not start pointing out that I have no "documentation" or proof to back this up. I do not.
Well, you DO have documentation to mostly back up 2-4... because I provided it in this very thread 2 years ago (and Lobuxracer had mentioned it before then as well in other threads), so it's pretty old news, and established as fact... it's part of those "other" things ECT-PWR does that you kept claiming I never admitted despite being the first to mention em in the thread, and continuing to do so.
Item 1 of 'what is happening' is likely wrong though- because folks would've noticed this happening in normal use when datalogging. The only timing retard that was noticed was right around the shift points... and we already know why it's doing that:
Originally Posted by Toyota
Engine Torque Control To prevent shifting shock on some models, the ignition timing is retarded temporarily during gear shifting in order to reduce the engine’s torque. The TCCS and ECT ECU monitors engine speed signals (Ne) and transmission output shaft speed (No. 2 speed sensor) then determines how much to retard the ignition timing based on shift pattern selection and throttle opening angle.
Item #1 of what is NOT happening is provably wrong for snow mode (though I know you were only quoting PWR), and plausibly wrong, but not proven so, for PWR mode based on what I mention in the post above this one above (including suggested ways to know for sure) and toymotas reply to you as well
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Not from my own experiments. If I hold the gas pedal constant and switch between Normal and PWR, the rpm do not change. If the throttle map is changing, the rpm would change. Right?
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And FWIW, the new GS (which runs the same transmission as the 350, just "improved") explicitly states that its various "modes" change the throttle map
http://www.lexus.com/models/GS/image...S-Brochure.pdf
(scroll down to driving modes)
We of course can't know for sure, from that, that ECT-PWR is changing the throttle map on the IS, but between that and the fact we know for sure snow does, and that PWR did in older Toyota/Lexus transmissions, it sure seems likely it's still doing so now.
The "easy" test of course would be someone find a reliable way to run a fixed gas pedal position (Hey Balanced, we could finally use those robots now!), put the pedal at 20% on a flat, straight, road and check the speed you maintain at.
Now switch to ECT-PWR and wait a minute or two. Did your speed or rpms change? (even better of course would be if you could data log the throttle position- that'd tell you exactly how much, if any, the throttle opening changed switching to PWR from normal at the same pedal pressure.)
http://www.lexus.com/models/GS/image...S-Brochure.pdf
(scroll down to driving modes)
We of course can't know for sure, from that, that ECT-PWR is changing the throttle map on the IS, but between that and the fact we know for sure snow does, and that PWR did in older Toyota/Lexus transmissions, it sure seems likely it's still doing so now.
The "easy" test of course would be someone find a reliable way to run a fixed gas pedal position (Hey Balanced, we could finally use those robots now!), put the pedal at 20% on a flat, straight, road and check the speed you maintain at.
Now switch to ECT-PWR and wait a minute or two. Did your speed or rpms change? (even better of course would be if you could data log the throttle position- that'd tell you exactly how much, if any, the throttle opening changed switching to PWR from normal at the same pedal pressure.)
As much as I've read from the manual, timing is only retarded in normal mode and line pressure is varied to smoothen shifts in normal mode. The trans shifts faster (just like the new GS) and uses clutch lock up in pwr mode,...I want to say only pwr mode, because I have not seen it mentioned for normal,...more reading. Actually, I may be wrong there about clutch lock up in 4th gear, because it does not shift into 4th gear if the trans is cold. It says varies line pressure, which to me means decreases and increases according to mode.
The manual does not go into great explanation detail because it was written for troubleshooting, removal and installation, not divulging information.
I think someone mentioned way back in the thread, but yes, if you held a fixed pedal position while in normal mode and select pwr, road speed increases. I would have to hook up my laptop to see if the throttle position changed (my belief) or if it was strictly a fuel map change, but it's doable
Last edited by clubfoot; Aug 23, 2012 at 08:40 PM.
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Oh, by the way, do this one experiment too if you can.
Fill up the gas tank with regular 87 and switch to PWR mode.
Due to the retarded timing, the engine runs flawlessly as opposed to Normal where it has to retard based upon the knock sensor signals.
Fill up the gas tank with regular 87 and switch to PWR mode.
Due to the retarded timing, the engine runs flawlessly as opposed to Normal where it has to retard based upon the knock sensor signals.
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Jeff
There are only two maps stored in memory in the ecu for our transmission,...normal and pwr.
As much as I've read from the manual, timing is only retarded in normal mode and line pressure is varied to smoothen shifts in normal mode. The trans shifts faster (just like the new GS) and uses clutch lock up in pwr mode,...I want to say only pwr mode, because I have not seen it mentioned for normal,...more reading. Actually, I may be wrong there about clutch lock up in 4th gear, because it does not shift into 4th gear if the trans is cold. It says varies line pressure, which to me means decreases and increases according to mode.
As much as I've read from the manual, timing is only retarded in normal mode and line pressure is varied to smoothen shifts in normal mode. The trans shifts faster (just like the new GS) and uses clutch lock up in pwr mode,...I want to say only pwr mode, because I have not seen it mentioned for normal,...more reading. Actually, I may be wrong there about clutch lock up in 4th gear, because it does not shift into 4th gear if the trans is cold. It says varies line pressure, which to me means decreases and increases according to mode.
Because that would explain why you don't think snow mode has its own map since it didn't exist then... and why you think it won't go into 4th when it's cold (when it's actually 6th it won't go into on the ISx50)
I don't think I'd want to draw too many firm conclusions from a 20 year old manual for a completely different transmission though...
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I tried this a few days ago and on my 2012 IS350C when I put the speedometer on 60mph and hold it there by keeping my foot against the side kick panel then push to power the car speeds up and the RPM also go up. It also slows and RPM go down when pushed to snow. It is very noticeable too. Just my observations that have no data to back them up other than I have no dog in this fight and wanted to try it.
Jeff
Jeff
I'll try again. No harm in doing that.
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I tried this a few days ago and on my 2012 IS350C when I put the speedometer on 60mph and hold it there by keeping my foot against the side kick panel then push to power the car speeds up and the RPM also go up. It also slows and RPM go down when pushed to snow. It is very noticeable too. Just my observations that have no data to back them up other than I have no dog in this fight and wanted to try it.
Jeff
Jeff
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err...are you still operating out of that 1990s manuals for totally different transmissions?
Because that would explain why you don't think snow mode has its own map since it didn't exist then... and why you think it won't go into 4th when it's cold (when it's actually 6th it won't go into on the ISx50)
I don't think I'd want to draw too many firm conclusions from a 20 year old manual for a completely different transmission though...
Because that would explain why you don't think snow mode has its own map since it didn't exist then... and why you think it won't go into 4th when it's cold (when it's actually 6th it won't go into on the ISx50)
I don't think I'd want to draw too many firm conclusions from a 20 year old manual for a completely different transmission though...
In my experience in winter, my transmission will not shift out of third until at least four bars of the temperature gauge rise.
Yes, 6th gear also takes a long time too depending on temp. This may have changed with the new ecu flash I had done for the brake pedal recall, so going by memory for now. Winter isn't too far off, so I'll have a chance to see the new flash in action.
I'm not saying for certain 4th is locked up, but in the manual it says it will not lock up until a certain temperature is reached to prevent damage,....so it's a guess :-)
I won't have much time this weekend to read as I'm helping my son with an MR2 Turbo engine swap for one of his customers, but I'll see what else I can pull and make a text fill with all the tid bits so we can discuss further.
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OK,...this is what I was able to grab with my tablet directly from the manual quoted:
The ECM memory contains the programs for the Normal and Power shift patterns and lock-up pattern.
ECT snow is the system that operates the throttle motor to control engine output to reduce skidding of the driving wheels, guarantee take off acceleration,driving straightness and turning stability.
The ECM memory contains the programs for the Normal and Power shift patterns and lock-up pattern.
ECT snow is the system that operates the throttle motor to control engine output to reduce skidding of the driving wheels, guarantee take off acceleration,driving straightness and turning stability.