Bad, Bad, boy !

Never, ever pressure wash under the hood ! Ever !
Water gets into electronics, connectors, and , and, well, you found out what happens.
I recommend getting it to your professional MB technician and have him check everything over.
I get about one vehicle every 2 months driven (barely) or towed in to my shop because of this 'self-created' problem.
I hope you did NOT damage/shortout any sensitive electrical components. ($$$$$$$)
Hope others out there are listening to me.