P0628 code w/ Aftermarket Lift Pump. Help!

[Lifted94XLT]

Hey guys, its been a long time since I've posted on here, and this is my first time in the 3rd Gen section of the site. I just bought a used 03' 3500 6spd with a TST Powermax CR, FASS fuel pump (with filters) and 4'' TB. I had a CEL show up the other day and have been doing some research on them. I'm getting a P0628 (Fuel pump circuit low), P0657 (A/C Clutch Relay Circuit Low), P0606 (ECM Internal Fault), and P0341 (Cam Position Sensor Circuit). I've done plenty of reading on the P0341 code and am gonna start checking out the wiring harness this weekend for a ground short, but my question is with the P0628 code. From all the reading I have done, it seems like its a sign that the lift pump is going out and everyone suggests replacing or upgrading the lift pump with an aftermarket unit (like the FASS that is already on my truck). My questions is just that, I already have the FASS on the truck so why would the code still be there?? I've have cleared them all once and they came back leading me to believe that there is still an issue. The truck seems to run and idle great (this is however my first CR 5.9). The only "issue" I seem to notice is a long crank before fire on startup, and that is everytime I start it. And also, intermittently, it will idle around 1100RPM. Any suggestions from the local experts here?

--Ryan

 

[SixOhh]

fun fun fun.... well for starters, i know for a fact that 0341 and 0657 are on the same circuit. I fought the same thing a few years back. Starting with the harness is a good idea.

i have installed over 10 airdog's and never had the 0628 after the install. Did the installer unplug the plug from the factory pump or splice power/ signal from anywhere they weren't supposed to?

im not a fan of FASS, but AD kits come with a Duetch connector that kills the factory pump in the tank and also supplies you with the signal wire from the ECM.

one more thing... do you have a gauge on the FASS? are you SURE you are putting out pressure?

 

[SixOhh]

one more thing.... unplug the TST till you get the rest of the problems figured out. always get the truck as close to stock as far as electronics go. then start diagnosing.

good luck

 

[Lifted94XLT]

fun fun fun.... well for starters, i know for a fact that 0341 and 0657 are on the same circuit. I fought the same thing a few years back. Starting with the harness is a good idea.

Yeah, I'm planning on checking out the harness for a ground short somewhere.

i have installed over 10 airdog's and never had the 0628 after the install. Did the installer unplug the plug from the factory pump or splice power/ signal from anywhere they weren't supposed to?

I'm not sure, I bought this truck w/ everything on it (only had it a week). What/where do I need to look to find out?? I'm dumb on these CR engines right now. My last Cummins was a 12V. Different universe. haha

do you have a gauge on the FASS? are you SURE you are putting out pressure?

No... and no. I need to hook up a gauge I guess. I would assume its putting out plenty of fuel as it smokes a decent amount on the lower power levels of the TST. I know that doesn't necessarily mean anything though.
Sounds like an excuse to buy a new tool. Diesel Fuel Pressure Tester. I assume a Diag Scanner would show that value though too. What kind of pressure should I be looking for as "normal" with the FASS (unfortunately I'm not sure what size pump it is (GPH))

and on your second post, the truck came with a bypass connector so I will try and do that this weekend before I start the diag process.

Thanks for your help and anymore help you can give me.

--Ryan