ECU always on

[jefurlan]

Hello guys. First post here. My W204 200GDI (gasoline engine) started draining the battery. With my scanner I manage to find that the engine electronics are always on. The central gateway gives a code u116000 “bus keep away detected” so I started checking circuits and found that the relay for circuit 87 in the front SAM is always on (and feels warm) removing the relay for testing turned off the ECU and this stopped the battery drain. Any idea that could help finding why this circuit is always on? Relays for circuit 15 do work correctly, but when checking outputs for the circuits I get “circuit 15x ON” on the front SAM despite “circuit 15x off” on the ingnition

 

[Blobcat]

Hello and welcome

No water damage in the front SAM is there?