Hi David, you are running into one of the odd imbalances in Latin: it has a present active participle, and a perfect passive participle - but it does not have a present passive participle, nor does it have a past active participle. This leads to all kinds of oddities in the world of participial constructions.
It is perfectly okay to say Ad solem nimio accedens, in mare cecidit. There is no perceived problem there with the present participle; Latin "knows" you don't have a choice between a present active and a perfect active participle, so the need for active voice outweighs the question of verbal aspect (participles do not have tense; they only have aspect).
Note that the verb accedo really does like to have the preposition ad: http://athirdway.com/glossa/?s=accedo
- that's why you run into trouble trying to use accedo in the passive. This is not really a transitive verb (it prefers a prepositional phrase rather than a direct object). "Sole accesso" really does not make sense as an alternative. "Sole alis tacto" would work - "the sun having been touched by his wings" - so if you felt a compelling need for an ablative absolute, that is what you would need to do I think: Sole alis tacto, in mare cecidit. Or something like that.
But it seems to me there is no need for an ablative absolute there - exactly because Icarus is your focus the whole time: Icarus approaching the sun, Icarus falling.