faulty diode?

hi all, i am quite new to the electronic world, so please take it easy on me

anyways, i have this electronic equipment (electronic boost controller) on my car and my mechanic said the unit is faulty, it turns on and stuff, but doesnt send any signal (to the solenoid valve unit) so i opened it up, and next to the noticed that one of the diodes has been burnt out or something at the legs. I circled it in the picture in red and if anyone could give me their expert advice. (ignore the red and blue light, its from my camera)

does it look burnt out or something because it looks like that theres black stuff that smudged the solder bit.
Any help would be appreciated. Thank you

what made u suspect that the diode is burned.?
any way to make sure its condition, disconnect one lead of the diode from the board and check for diode continuity

It looks to me that it arced to ground. The diode may be ok but whatever caused the arc is the problem.

so you reckon i should take it to a specialist? because thats what i might do. hopefully it will be fixed. Will keep yous informed