Hysterisis issue on TPS load gear table

[gboezio]

Wow that does it, it drives almost perfectly, just have some fine tuning to do, I had no gear hunt no low or higher speed glitches, I had to set speed hyst to 10 km/h and load hyst to 7% for my setup at least for now, WOT is unchanged, kickdown goes smoothly.
The reason why I had to set a high speed hyst is that load and speed were increasing linearly would cross a first gear bin and make it downshift, otherwise it would go smoothly at hyst=5km/h

The log included is smooth operation with final settings

I could accelerate while varying the throttle smoothly while staying on gear and as soon as would go harder on it it downshifted perfectly everytime.

On a totally different note I had to edit the INI to raise the Hystersis enable maximum setting to 22, it's 15 for both MPH and km/h and we metric need a bit more on the km/h max settings, I needed this because for some obscure reason (maybe I need to set lower line pressure colse to low speed) on second gear and up the trans is killing the engine, means that I have to hold the truck with the brakes and this will stop the engine, the only fix was to set one bin to 20kmh and the other to 26 and to enable hyst @ 21 kmh (20 is the speed were second gear gets at idle RPM) (I may start a new thread on the 4l80E behavior)

Thanks for awesome support !!

Giovanni Boezio

[Bernard Fife]

Giovanni,

I'm glad that helps. I have edited the speed hysteresis limits to be 25 kph/15 mph for the 4.126, 5.002 and all future INIs. They are here: http://www.msgpio.com/manuals/mshift/files/ini/

Many thanks for your patience. I'm not sure about the 2nd gear issue, but I am sure we can get it sorted.

Lance.

[gboezio]

I will add here a few small glitches that you may want to correct whenever you want, I caught two so far

1-TCC will lock under the limit temperature, the transmission seem to stay just warm for real (touch-O-meter), it will heat up just by staying in gear idling

2- Reverse line pressure is smooth since you fixed the 100% reverse pressure, it does not cirp the tires upon high idle, but it logs 245% while putting back into forward gear without real problem I can remember, maybe a heavy clunk (there are many on a leaf sprung Jeep), it does since a while maybe since the reverse pressure fix, I just noticed it.

MSQ is the same as before

[Bernard Fife]

gboezio,

Okay, I will have a look!

Lance.

[Bernard Fife]

Giovanni,

Here is some modified code you can try:

Monitor_4126b.abs.s19

Use standard 4.126 INI. Use code with caution!

(71.05 KiB) Downloaded 617 times

This code has some fixes for both the TCC issue (related to 'full-time' STCC settings being improperly applied) and the line pressure glitch (related to the shift function using an out-of-bounds array index for the line pressure limit when shifting from P, N or R).

This code uses the regular 4.126 INI. No user parameters were added, and no other part of the code was altered. However, I have not tested this code at all, so use with caution.

These might not fix your issues, but the issues addressed could certainly cause the symptoms you describe. If these don't fix them, we can look deeper!

Lance.

[gboezio]

Hi Lance, I have tried the test code, it did fix the reverse to Forward PC% spike, but it did not fix the TTC locking before reaching set temp, that said, below 42,3 there is no locking at all, the logic is there and working, but it operates 17,7 degrees too low. The formula to convert celcius to Farenheit is multiply C value by 1,8 and add 32, the 32 degree F added is equal to 17,7 in degree C, I should have figured that out earlier.
Ah metric people

Thanks
Giovanni

[gboezio]

I have found a glitch on the full TPS gear table hysteresis, I did not notice it earlier since roads were too busy for 4 th gear long term operation.
When the trans shift in 4 th gear, it will not downshift in 3rd, unless I break speed hyst or unless I hit the second gear bins, then it will (set to sequential) downshift in 3 rd and 2nd, it does not do this on the other gears, it works seamlessly except a second gear hang that I'm investigating in my settings

Giovanni

[Bernard Fife]

Giovanni,

It looks like your CAN comms aren't perfect, this is shown by the occasional 3.0 error values in your log (1.0 is no errors). CAN errors can certainly prevent shifts. So you might want to recheck those connections and make sure they are 100% good.

However, I think there is more to this than a CAN issue. If you get a chance, could you try the 4.126d code from this thread: viewtopic.php?f=4&t=662&p=3547#p3546 ? Also, could you update your INI to the latest 4.126 here: http://www.msgpio.com/manuals/mshift/fi ... t_4126.ini as it logs the TPS position that MShift sees.

In the mean time, I will be looking through the code, and will post back here when I find something that could cause the issue.

Lance.

[Bernard Fife]

Giovanni,

Could you try driving with the rev liming turned off to see if it helps the 'no-shift' issue? This is under 'General Settings -> Rev Limits -> RPM Checking'.

When I do this on my bench, all is well. It is very hard to test the rev-limiting properly on a bench though, as the ratios need to be considered at all times for both up and down shifts. I will have a look at it, but if you could say if shutting this off helps or not for you, that would narrow it down.

Lance.

[gboezio]

Thanks Lance, I will try 4,126d tommorow if the weather permit.

As for the TTC lock temperature issue I have found it, the problem was on the INI file
I have edited the INI for the no hyst below speed maximum and conducted a search for 5556 and have found the translate bin = 0.00000, I have set it to 32.0000 for my next datalog ride.