I am getting A P-1690, P-1694, and P1693. I know the 1693 ends up being the Maps sensor. I replaced it about a month ago. The 1690 is a communications error between the injector pump sensor and the engine sensor. There are a lot of variables to consider when reading possible fixes. Is there a most common problem I can start with before heading to the injector pump with this? Thanks in advance for all help.

 

P1693 is a companion code, you need to read the other computer to see what that code really is.

I am betting it is a VP related code such as P1688 or 89.......

For good diagnosing info on the VP, go to bluechip diesels site, best info on the VP I have seen.

 

Yes the 1693 is a companion. The code pulled from the OBDll is the 1690 code.