Intake system
But, 1999 and earlier engines with code "ABE" use N122 as the coil driver (I think Bentley has a typo here, cause my '99.5 engine code is AEB not ABE). Didn't see any sensors associated with N122, just seems to be a heatsink for the power transistors.
Why would they measure the unpressurized air temp in teh airbox to control timing? It really doesn't make any sense. Then what's the use of the Intake Air Temperature sensor G42 at the throttle body? I would think the air temperature through the throttle body after the turbo and intercooler is more important for determining ignition timing. After all this temperature is closer to what is actually entering the cylinders.
This is not an attack on your post, I'm not an EE nor English major(as you can see in my writing =P). I'm just raising some questions. AFAIK N122 is not a computer, honestly I don't know exactly what it does but I really don't think it does any kind of temperature measurement.
This is what I gathered from the Bentley. I could be wrong tho.
G42 definetely feeds back data to the ECM for processing. N122, on the other hand, has no power source other than the signals coming from the ECM. How can the module be amplifying the signal without an external power source. I view it as a signal modifier and not as an amplifier.
What would be interesting is to see is how the signal is modified by N122 with a change in temp. I may pull it this weekend (or Monday during the storm) to see.
Mike O.
Bringing Audi to Life for Audi Fans


