Consumption Data: Where to Get It?

I plan to install an auxiliary heating system (AHK) with a coolant temperature sensor (FIS) in my A4. I already have all the necessary parts, but I'm missing the connection point where I can tap into the consumer signal from the engine control unit (ECU).

Where is the best place to intercept the signal?

I suspect you have an MSA15 (e.g., 028 906 021 FE).
Engine Control Unit Pin 9.

Best regards,
Rudi

Okay, I'll check that out later.

Okay, so pin 9 is already occupied on my setup and is connected to the main cable running towards the motor. I have a 028 906 021 BD. Or, is there perhaps another place where I can connect it?

"In my AFN system, this signal was present in the wiring harness. It makes sense that it would then be present on the connector! I don't know if it's pin 9. I only know that I once connected an oscilloscope to it - then you get nice, short pulses, and the more pulses you get, the more fuel is being injected."

021BD is an MSA15.5 Pin 9.

"You're right, it comes from Pin 9, but I didn't want to tap into anything on the control panel. I've now taken the connection from the plug socket in the water tank, using pin 3 and the yellow wire."

What's the difference between an MSA15 and a 15.5? Is it just a model update?

As far as I remember, this cable runs from the fuse box to the tachometer unit. So, you should be able to access it relatively easily somewhere in that area. In my T3, it's currently disconnected and hanging loose.

What is the difference between an MSA15 and a 15.5? Is it just a model update?

No, just a clarification: The control units with the part number 028 906 021xx MSA15 have the MSA15.5 designation (68-pin connector).
and the 038 906 018xx models are MSA15.7 (same processor core, but different socket - namely,
two).

Best regards,
Rudi