1997 Blazer code 1402

Does anyone know what the code 1402 on a 1997 Blazer S10 is for?  It came up on the machine, but isn't in the book.

Are you sure it was P1402 or was it possibly U1402???

U1402 - Loss of Class 2 serial data communications

That is the only 1402 code that pops up...

Thank you, that was the code the guy said.  There was another website that said it might be EGR.