so my buddy has a code p-1688,the obd says internal problem,low power or engine stopped.
it pops up as soon as he starts it.the fuel pump is in the tank he hasnt got a fass or air dog yet .what ideas do you intelligent diesel lover's got? it is an 02'-24 valve . history unknown as he bought the frame with engine and diffs and tranny.
it does run rough

 

I read somewhere that it's an injection pump issue. either that, or it's sensor is probably going or gone. just my idea, somebody with more experience will probably help out more, Good luck!

 

P1688 Internal Fuel Injection Pump Controller Failure

Check the connection on the top for corrosion. If corroded, use some battery terminal cleaner or WD40 to rid the corrosion. If it doesn't help, VP44 is it's last leg.

 

Any updates??

 

he found out the pump was nfg like they all do sometimes thanks guys

 

Resolved and closed.