Buds system at the Dealer or Candoo Pro if you want to DIY.
Funny this stuff comes up as I just reset the maintenace light tonight on my 05 GTX using the Candoo system well worth the money especially if you can split the cost with another Seadoo owner. I have used it to clear fault codes, reset maintenance indicators, enter the correct owner info and program all my keys to both my machines. All this would normally require a trip to the dealer.
My friend went to the dealer to get another DESS key for his GTR and the dealership wanted him to bring the Seadoo in as part of the price for the key they didn't believe him when he told them he could do it himself and just needed the key.