The best way I've found to determine part numbers s to go to an online Acura parts dealer, like oemacuraparts.com, and find the part.
If I was you I'd contact that dealer and tell them you think they neglected to reinstall it after the last service and you'd like them to install one - either your old one sitting off in a corner, or a new one they can provide - at no charge of course.
If I was you I'd contact that dealer and tell them you think they neglected to reinstall it after the last service and you'd like them to install one - either your old one sitting off in a corner, or a new one they can provide - at no charge of course.