My 09 FLHX is putting on a check engine light for about 10 seconds after it starts. There are 2 codes stored, P1003 System relay Contacts Open EFI and U1300 Serial Data Low TSM/TSSM. Any ideas on what these could mean? The bike is all stock except for a pair of slip ons.

 

I think that '09 means you should take it in to the dealer. I would start by making sure the connector is firmly plugged into the ecm. When you pull the electrical cover it's the big connector at the top.