I have a 2004 S60. I am having intermittent electrical problems. I have noticed a buzzing sound near the TCM ECM. This lasts for a few minutes after turning odd the ignition. I can hear a relay (FM2A) release and the buzzing sound stops. Is this a normal sound?

 

I believe there is a an ECU fan to keep it cool and running for a minute or two after shutdown is normal, but perhaps someone else will confirm for sure.