Audi A6 TDI Engine Control Unit "02" (C4 AAT)

Hello.

I'm not 100% sure if my Audi A6 TDI (year 1995, C4 model, engine code AAT) has a transmission control unit, but in any case, I can't access that controller with my diagnostic interface and VAG-COM software.

Could someone please tell me where I can find this control unit and how to identify it so I can spray its connector with 'contact cleaner'? (Spraying the connector of Control Unit 17 [Instruments] with contact cleaner resulted in partial success: I can now at least communicate with the control unit. Although I can't make any changes [like resetting the service interval], I at least know that the control unit is present).

Best regards,
Oded.

Hi,
Does your car have an automatic transmission?
If not, you can search for the STG for a long time.

Best regards, Rudi.

No, Rudi, my car doesn't have an automatic transmission.

If you go into the 'Auto-Scan' function within the VAG-COM software, it will first display a list of all the control units (ECUs) present in the vehicle. In that list, I saw 'Controller 02.'

Are you saying that my Audi doesn't have a 'transmission controller'?
Best regards,
Oded.

Hello Oded,

What purpose would you see for a control unit in a purely manual transmission system?

Hello Michael II.

Allow me to respond with a counter-question:
What function does the control unit fulfill in an automatic transmission?
What can the diagnostic system determine or change via the OBD interface?

Now I've noticed that in older German versions of VAG-COM, in the main menu, under '02', the text reads: 'Schaltautomatik' (which translates to 'Automatic shifting'). In another version, it says: 'Getriebe' (meaning 'Transmission'), and in the English version, it says: 'Auto-Trans'.

Best regards,
Oded.