2012 Isx 2350 475 with codes 4726 and 0559

[Rawze]

(01-22-2022 )ahrenbenjudah Wrote:  I’m assuming you mean the mechanical one as opposed to the lift pump yeah?

yes, if the main fuel pump fails, it destroys the entire engine .. literally ... along with it in only a few hours of run time. It is nothing to play around with at all, and that 559 code is the most common code that comes up when this is happening.
ref: http://rawze.com/forums/showthread.php?t...9#pid15389

hope like h$ell that the fuel pump has not failed. Pull the head off it and inspect it.. replace its guts if they have more than 8,000 of run time on them, or 400k miles. the guts ( tappets, rollers, plungers, etc.) of the fuel pump needs replacing every 400k miles on all model ISX engines that have a common rail to prevent this.