You brought it to the dealer and they didnt det the code to work after they disconected it . If the radio says error on the screen you entered the wrong code to many times and it went into lock out mode you need to disconect the battery and turn the ingtion to the on positon trurn it off wait 5min reconnect the battery turn the radio on it should say CODE on the screen then put in the code it should work.

If that dosent work make sure the radio says CODE and disconect the antenna wire from the back of the radio ( you may have to pull the radio) leave all other connectors in place and try the code again

If you live in New York call me I own my own repair shop 516-385-6401