vss failure saftey function??

[zen]

would it be possible to have an emergency over ride saftey fucntion??
ie if gpio loses vss signal BUT engine revs are above ( so dont cut in at stand still) a PRESET amount then gpio selects A PRESET gear..ie 3rd??..thus saving killing drive train..possible crash etc..

this is the case on my OE bosch controller..

thanks

[zen]

i ask as i dont see how the stop gear change if over rev facilty will work if gpio has no vss input..if it dont know road speed how can it determine if its going to over rev if it changes down from say 4th to 1st..ie say doing 60mph then loses vss, so thinks ohh, better change into 1st as stopped..

[Bernard Fife]

Zen,

I have been thinking about this too. I have pursued a slightly different approach, which is to estimate the vehicle speed from the rpm and gear ratios. If the estimated speed and VSS dramatically disagree, then block downshifts. I have been working on this in the 5.xxx code, and hope to release something soon (the 5.xxx code is about to get a number of other new functions and features too, like RPM based shifting (which would likely solve your problem too), NAG mode, new serial envelope compatibility, etc.).

Lance.

[zen]

kool..thanks..

please let me know when done..would you advise using a beta on road going car??

[Bernard Fife]

would you advise using a beta on road going car??

Zen,

At this point, you should only use the beta code on a road car if you had first tested all critical aspects of it thoroughly on the bench in the configuration in which it was going to be run on your car (i.e. with your msq).

There is a beta in the works that has a large number of improvements (VSS is better, has the new serial envelope format, has a NAG mode, etc.) but this also requires quite a lot of testing. I am hoping to verify as many functions of this code as possible prior to release.

In general, I have only been verifying the changes plus a few critical functions (serial/CANbus comms, flash burning, VSS, auto shifting, solenoids, and a few things like that) for recent releases, as these changes have generally been small. But it been long enough, and the changes are substantial enough, that it's a good time to retest all functions from scratch. At that point the beta code should be good for careful vehicle testing.

My intention is to release the new code as 5.090 (for use with 2.920 and earlier code)/6.090 (for use with 3.830+ code plus potentially MS3 - with the new serial format) hopefully soon (it depends a bit on how many problems we find and how hard it is to fix them...). This code is a step towards the 5.100 release version, which ideally will follow shortly once enough users have successfully trialled it.

Lance.