called dealer today and ask about the code po628 he said low voltage to lift pump so I did not tell him I just installed the full fass. did anybody else get and codes after the full fass install? 2003 s/o thanks kully Ps truck never rain so good all the way around also quieter and also smoother

 

I got the code when I did FASS also. Because I'm a smarty and wanted to see if the truck would start without the Lift Pump. It does.

Took about 9 days for it to go away.
P0628 Fuel Pump Relay Circuit Low, or Fuel Lift Pump Control Circuit Low

 

so just leave it alone, pump has been for day 8 now and I just check codes today and saw it you say it will go away buy it self?

 

Well mine did. But it really did take me 9 days. Some days only put 9 miles on truck then others 100+; so that's why I was ok with 9 days.
I have heard on here that some things take a certain number of full cycles to clear. Just because I think the truck has had a full cycle doesn't mean it has.


ON EDIT - Did you check for codes prior to FASS?
Did you try to start the truck with the OEM pump disconnected? I know for a fact that's what caused mine.

One day last week another member had the exact same thing happen as us and was concerned. I have to follow-up on that one and see.

 

yes I did check for codes pry to install and did not have any. installed full fass and plumb to oem filter houseing started truck and ran fine .then I thought to remove oem filter and started truck again and loss pressure right away.so I reinstalled oem filter and left everthing alone .just today I thought to check codes as I did not check right after fass install,ment to but was just very happy about improvements so I thought to check today and found this code

 

How did this turn out Kully?

 

Is this popping the MIL? This might be because of the resistance differance between the Relay and Stock pump. The relay setup changes the resistance of the circut....i would guess it runs lower than the Stock LP. I am thinking that is the issue. If the light has not been, i wouldnt worry about it. I have gotten a few calls on this since the short time i have been here.......

 

sorry for not getting back to everbody I was on vacation, on the code thing it took several thousand miles to go away but I do not have it anymore