A8L Quattro Sedan W12-6.0L (BSB) (2005)
Engine Control Module: Service and Repair
Master Engine Control Module, Replacing
Master Engine Control Module, Replacing
Engine management is controlled by two engine control modules.
Both engine control modules communicate via private CAN-Bus.
Engine Control Module (ECM) (-J623-) (Master) shares with Engine Control Module (ECM) 2 (-J624-) (Slave) which functions need to be
performed.
The two engine control modules look identical. If both engine control modules are removed, they must be marked before removal to prevent them
from being interchanged when re-installing.
Master ECM 1: e.g. with "M"
Slave ECM 2: e.g. with "S"
Engine Control Module (ECM) (-J623-), removing
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Connect vehicle diagnostic, testing and information system (VAS 5051) and select vehicle system "01 - Engine electronics". Ignition must be
switched on.
On the screen of the vehicle diagnostic, testing and information system (VAS 5051), the control module identification and coding - 2 - are displayed.
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Allow control module identification to be displayed and then print it out.
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Remove right cover from plenum chamber.
Position 1 shows the Master ECM (-J623-).
Position 2 shows the Slave ECM 2 (-J624-).