Body control modules on modern day vehicles often get mistaken for just being a fusebox. They are so much more than a fusebox, they are a computer and many of them have a built in diagnostic capability.
This is the reason why it is important to not pressure wash the engine bay, and to always make sure you re-fit the cover if you have had to replace any fuses.
As you can see in the above pictures this is how easy your car can catch fire. As auto electricians we see time and time again water inside the engine bay fusebox module. The above pictures shows the BSM on a Citroen C2 that has shorted due to water ingress, damaging the module and has melted the wiring. With many car electrical repairs, this is going to take some time and accuracy to repair and make sure every wire is put back in the right place.
We repaired the damaged wiring having to back trace all the wires to their source as all the numbers had been burnt off the end of the wires. The wiring loom plug was replaced and then a new BSM was fitted to the vehicle. The customer was lucky their car did not catch fire and there was no further damage to the BSI unit.