Couple of things idle-related MS3/MS3X

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elaw
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Couple of things idle-related MS3/MS3X

Post by elaw »

I've been having some issues with idle control the past few days and have discovered a few things of possible interest...

In the manual, for the MS3X medium-current outputs (like "idle"), it shows a current limit of 3A. However on the datasheet for the IPS022G under "recommended operating conditions" it gives max. continuous drain current as 1A. What's up with that? I'm interested because my idle valve draws 2.8A at 12V, and of course probably more at the 14.4 volts that's usual when the engine is running. :?

BTW I think this has been discussed before but it would be *really* nice to have some other output options for idle control. I've got 3 unused injector outputs on the MS3X that would be perfect for this... but right now my only other option is to build a driver circuit on the v3.0 board. That's a heck of a lot harder than moving a wire from one pin to another on the MS3X! :(

Also, I'm running a version of the 1.2.3 firmware that I've customized, but I haven't touched anything related to idle control. In TS on the "Idle valve test" dialog it clearly states that it can be used with the "engine running or stationary" but it does NOT work for me when the engine is not running! The output remains off no matter what PWM value is selected. I spent over an hour pulling the MS box out of my car and looking for a hardware problem before I got the idea to try the "I/O test mode" screen which *does* work with the engine stopped. Is this a known issue or did I somehow break something?

.msq file and .ini needed to open it attached (although for looking at idle control, the standard 1.2.3 .ini should work).
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
jsmcortina
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Re: Couple of things idle-related MS3/MS3X

Post by jsmcortina »

Idle uses hardware PWM. There are only a certain number of hardware PWM channels on the chip - hence the pin restrictions. Features like boost use slower software PWM and can use any pin.

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elaw
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Re: Couple of things idle-related MS3/MS3X

Post by elaw »

I hate it when that happens! :lol:

Oh well, I guess it could be achieved with a little creative rewiring of the MS3X card...
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
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