Reset code for 2009 mdx acura radio after disconnecting the battery?

To reset the radio code for a 2009 Acura MDX after disconnecting the battery, you will need to retrieve the radio code from your vehicle's manual or the card that came with it. If you can't find it, you can contact an Acura dealership with your Vehicle Identification Number (VIN) to obtain the code. Once you have the code, turn on the radio, enter the code using the preset buttons, and press 'Enter' to unlock it.