Modifying Motronic 2.3.2 ECU hardware and software.

[-ice-]

Hi,

as I have seen in the code, there is a second rev limiter (two bytes next to the normal limiter), which disables some code. Why do we need two?

Regards

[prj]

Hi,

as I have seen in the code, there is a second rev limiter (two bytes next to the normal limiter), which disables some code. Why do we need two?

Regards

The second one is the "engine speed exceeded" fault.

[S2central.net]

This thread is mad - pure mad - hugely educational - technically and socially.

[-ice-]

Hi,

Was that irony?

Thx prj. So it's not good to trigger this limiter

To come back to FGAT. Yes it seems to be a FKT128 correction factor to enrich the mixture. In older Motronics they had coding switches on the circuit board to select FGAT0 to 4.
But in my opionion it wasn't meant as injector constant. It's more to adjust your engine to different fuel qualities...
But it would be possible to adjust the injection time with it. Hmm..

Regards

[vwnut8392]

are any of you guys good with the hardware aspect of the ECU? i have a spare 4A0 907 551AA ECU that has been on a shelf for around a year. a year ago the ECU worked but when i went to use it today i get a no start. The original ECU to my S6 starts the car and drives fine so that rules out any of the sensors on the engine. i have fuel because i can smell it but i have no spark. this leads me to believe there's something wrong on board in the ECU that its not outputting a signal to the POS's. is there a common piece of hardware in the ECU that goes bad? is this ECU pretty much a paper weight now?

[prj]

Hi,

Was that irony?

Thx prj. So it's not good to trigger this limiter

To come back to FGAT. Yes it seems to be a FKT128 correction factor to enrich the mixture. In older Motronics they had coding switches on the circuit board to select FGAT0 to 4.
But in my opionion it wasn't meant as injector constant. It's more to adjust your engine to different fuel qualities...
But it would be possible to adjust the injection time with it. Hmm..

Regards

Too much talk. There is base constant from which all further pulsewidth calculation is derived. Change this constant when you change injectors (and TVUB of course), and all will be well.

[-ice-]

I think i need to find a way to switch off the lambda control before i start to play with enrichment factors.

Bye

[Acki]

Look for the lambda threshold table. Nearly at the end it should be.
Rpm only map. Values 190,160,140. Have to look into your dump. ;-)
It's the load until lambda control is active.
With wide band you can see this very easy. :-)

[-ice-]

ok, thx ;-)

[Acki]

With wide band you can use the lambda heating control for some other stuff. ;-)

[Acki]

Ui. Sorry I also don't find it

[prj]

6x1 in M2.3.2.

First map for normal operation.
Second map for "Dauerklopfen".

[Acki]

At my v8 I have this map.
How do you mean for longer knocking (dauerklopfen) events? The enrichment? Lambda deactivation during knocking?

[prj]

Unneccessary questions. Read ME7 FR to understand "Dauerklopfen", and compare these two maps in binary.

[-ice-]

Ok the map i'm looking at has it's maximum (high threshold) at 3000rpm. So setting the value to 0 should disable the lambda control.