Is there a code to breed lendgedaryAR CODE in Pokemon diamond?

Yes, there is an AR code that can be used to breed legendary Pokemon in Pokemon Diamond. The code is:

94000130 FCFF0000

This code will allow you to breed any legendary Pokemon, regardless of whether or not you have the corresponding event item. To use the code, simply enter it into the AR code list in the game's menu. Once the code is activated, you will be able to breed legendary Pokemon by mating a Ditto with a Pokemon of the same species. The resulting egg will hatch into a legendary Pokemon.

Note: This code only works in the European version of Pokemon Diamond.