A0AA is a very common fault stored in BMW Car Access System (CAS). The fault can cause an annoying light and bing noise or even non start. You can carry out a reset using an Autel Maxisys system (i.e Maxisys Elite, MaxiSys MS908P etc).
Model example: BMW 630i coupe 2007
MaxiSys reads fault code: A0AA in CAS control unit
How to erase fault code A0AA?
In MaxiSys Elite scanner, go to Diagnostic Function->BMW->Manual Selection-> 6 series->E63/E64->630i_N52_COUPE->EUR-RHD->model year 2007_03
Confirm vehicle information
Select Service function-> Drive->CAS->Reset internal ELV fault counter
The internal ELV fault counter must be reset and a control unit reset performed after replacing the electronic steering lock.
Continue service function
Resetting internal ELV fault counter and performing control unit reset.
The internal ELV fault counter was reset.
Read the fault code memory out of the CAS control unit.
Service function finished
Go to Autel MaxiSys Diagnostic function and choose Auto Scan
Select CAS Car Access System
Then Erase codes
Codes have been successfully erased.
No fault codes detected.