first, check the fuse for it. i dont remember if that one is in the car or under the hood. if not, make sure one of the wires in the split harness didnt come loose. third, there is a "reset" button on the front of the stock head unit between a couple of the buttons on it. i dont remeber how to reprogram, but just call your honda dealer and ask their service dept. explain the situation and they're probably gonna tell you how to reset/reprogram the circuit. could be a bump made your stock reciever think that you were trying to steal it, and now it doesnt function, and you have to enter the code for it.