4L80E code

[Bernard Fife]

gui67,

The spikes to 0 are typically caused by the speedo resetting due to errors.

To fix this, you can:
- increase the 'Max. Errors to Reset' setting, and/or
- increase the 'VSS Input Masking' setting.

Both of these will reduce (and hopefully eliminate) the VSS reset issues. These are described here: http://www.msgpio.com/manuals/mshift/V4tune.html#gv

Lance.

[gui67]

Hello Lance,

I thik you have a 4L60e, which has the same sensors as the 4L80e, what values did you set these 2 parameters to?
Or could other 4L80e users tell me what parameters they use? I still get the transmission going to first sometimes (not so often as before, but still every 20 minutes appriximately.

I have a question about minimum speed for converter lock-up: is it possible to decrease the minimum speed to under 50km/h?
This is the speed limit in cities in France, and as I have a high RPM stall converter, I would like to have the possibility to lock it at ~45km/h to drive with lower RPM.
Is that possible? is it a soft modification, or can I do that in the ini?

Is it possible to add an hysteresis to the max tcc load? some times, the load is low enough to allow lock-up, then RPM decreases (a lot with my converter) which causes the load to go again above max tc load and unlocks TCC...

[Bernard Fife]

gui67,

The values I used are the defaults, however a fair bit of work has been done in that area of the code, so you may need to experiment.

The minimum TCC lock-up speed is set entirely by the INI (not the controller). You can change it by finding the lines in the INI like this:

Code: Select all

#if NOT_METRIC
  minTCCspeed      = scalar,  U16,   437,                    "mph",     0.10000,    0.00000,     30,    300,        1    ; minimum TCC lock-up speed (imperial)
#else
  minTCCspeed      = scalar,  U16,   437,                    "kph",     0.10000,    0.00000,     50,    450,        1    ; minimum TCC lock-up speed (metric)
#endif

and changing the values of 50 (kph) and/or 30 (mph) to whatever you prefer.

Lance.

[gui67]

Hello Lance
The car has a tendency to stall due to fuel pump problems at the moment

speed start.msl

. When that happens, i have to put the car in neutral to start the engine again. But if i do it while driving (vss >0) the transmission stays in first gear and will not upshift, either automatically or manually.
I have to stop, put it to neutral, to D and then start again.
I attached a log of that happening.
Could you please look what is going wrong and if it is possible to have it shift normally after starting the engine not at a stop.
thanks
Guillaume

[Bernard Fife]

Guillaume,

That's scenario that isn't anticipated in the code (stalling but not stopping). I will have a look at it and see what can be done. The work-around is to fix the fuel pump, but you likely knew that already!

Lance.

[gui67]

Hi Lance,
I am working on the fuel problem to try avoing stalling.
Yesterday, while testing the car, I accidentaly put it in neutral while cruising (I thought the lever was on 3, so I pushed it, but it was oalready on D, so I shifted to neutral.)
Putting it back on D made the same result: the transmission stayed in first. I had to stop, put to N and then D again to have it work correctly.

[Bernard Fife]

Guillaume,

I am looking through the code, trying to find a good solution for this. The difficulty lies in distinguishing between a true shift to neutral and a faulty or intermittent shift lever signal(s).

I will attach some 4.140 test code that might help. It as a few subtle changes that may fix your issues (or may not...):


<edit>Code S19 file removed, see below.</edit>

GPIO_MShift_4140.ini

(218.16 KiB) Downloaded 474 times

I have not tested this code at all, I wanted to get it out for you to try asap.

Lance.

[gui67]

Thanks Lance,

I will try it this week-end i the weather is nice.
I will let you know
Guillaume

[Bernard Fife]

Guillaume,

Attached is an improved version of the code in the earlier post:

Monitor_4140b.abs.s19

(72.67 KiB) Downloaded 474 times

This code uses the same INI as the prior code (get it above).

I will remove the older code from my earlier post so there's less chance of confusing them.

Lance.

[1991blazer]

My 4l80e install will do the same thing if I put it into neutral while driving. It seems to stall the code for the shifting, stopping and putting into Park will get it shifting again. I will try the code you posted.