Code PO477 exhaust pressure control relay low

[LPChristensen]

I checked my code reader today and low and behold, the engine was throwing a code PO477. Anybody got any idea what this is and more importantly, what does it do? I have a Jacobs exhaust brake, as well as a 4" flow through muffler, but they and the Edge EZ have been on the truck for over a year and I never got this code. I would really appreciate any advice from you guys. I don't want to take it back to the dealer unless I can really help it, the diesel mechanics there really do not inspire my complete confidence.

 

[Bob4x4]

The description of the code is low voltage on the engine brake driver. Possibilities are fuse,wiring,relay or ECM.



Bob