Modifying Motronic 2.3.2 ECU hardware and software.

[RichLV]

I wanted to have a crack at Motronic as well, I have extensive background in electronics and programming but after reading this thread I'm leaning towards getting a VEMS unit as suggested by multiple people to get a hang of mapping.

Bit of offtopic but I was wondering if someone has seen a base map for stock AAN for VEMS circulating around somewhere?

[-ice-]

let's get back to topic...

I'm wondering how actual rpm and throttle position are transfered to the boost/knock controller

Regards

[prj]

let's get back to topic...

I'm wondering how actual rpm and throttle position are transfered to the boost/knock controller

Regards

Exactly the same way as fuel/ign controller.

[-ice-]

Hi,

I have absolutely no idea how this could work...
All three mcus are connected together through the serial lines ok.. 80c535 usually have tx (P3.1) and rx (P3.0) pins.
As far as I know you always have to connected a tx wire to a rx receiver (crossed). I can't prove this on the board. I'm not sure but i even think the tx are clamped together... how could this even work when two devices send simultanesouly?

is there some kind of loop-back modus used?! I'm not sure who talks to whom here...

Regards

[-ice-]

Aha it might be this synchronous shift register mode...

Bye

[prj]

Hi,

I have absolutely no idea how this could work...
All three mcus are connected together through the serial lines ok.. 80c535 usually have tx (P3.1) and rx (P3.0) pins.
As far as I know you always have to connected a tx wire to a rx receiver (crossed). I can't prove this on the board. I'm not sure but i even think the tx are clamped together... how could this even work when two devices send simultanesouly?

is there some kind of loop-back modus used?! I'm not sure who talks to whom here...

Regards

Come on, you are overcomplicating this.
I told you - the boost/knock controller gets the signals EXACTLY the same way as the fuel/ign controller does.

THINK.

[-ice-]

Hi,

let's take the throttle position. To get the throtte position fuel/ign controller reads the ADC. But the throttle potentiometer is solely connected to the adc of the fuel/ign controller

Bye

[prj]

But the throttle potentiometer is solely connected to the adc of the fuel/ign controller

Nope.

[kymi]

-ice-, you must know what's the ram address for the throttle position used in maps. Search that ram address. It's not direct feed but trace a couple steps back. It seems to be the nature of this boost-chip.

[-ice-]

my eyes are tired, but after looking at it, i think the throttle signal is also connected to the adc of the boost chip

thank you

[prj]

my eyes are tired, but after looking at it, i think the throttle signal is also connected to the adc of the boost chip

thank you

Touche.

[-ice-]

kymi, what about RAM 0x5D?

Bye

[prj]

Don't have the ida project on this computer, but which 0x5D are you referring to?
Boost chip axis?

[kymi]

-ice-, nothing. Just tried to help you a bit.

[-ice-]

Yes Rs2 551c boost chip...

The analog input of the tps is put into 0x5d internal RAM and used in many routines (boost control, overboost calculation etc.)

I dont't have much knowledge about the boost chip at the moment. I can tell you from the code which map is read. But i don't know anything about the axes. Just that rpm and tps are used as axes.


Bye