Have a BD Diesel lift pump. Truck started bucking then stalled. Jumped from battery to pump and truck started but wouldn't run much above idle. IBDII showed Code P0628. Cleaned terminals on pump and opened water drain on filter housing and had pretty good fuel flow with the pump on. Re-installed original wires and tried to erase the code, Wouldn't erase?? Started truck and drove 130 miles to home with out a problem. Checked code again when I got home and still have two codes showing both P0628 with one pending. Still unable to erase!
Any suggestions??

 

Sound like you need to trace and double check all the fuel pump wires from the pump all the way to the fuse box..

 

With that in mind, where is the fuse for the fuel pump? I looked at every fuse/ relay in the fuse box and nothing is marked "fuel pump" The only ones marked fuel anything is the "fuel heater" fuse and relay.

Now the interesting part. This morning I used my "better" OBDII and it was able to erase the codes??
I'll be keeping that one in the truck with the extra pump.
Thanks for your suggestion. The harness that came with the pump connects to the OEM harness at the OEM filter so that is easy to check.
Thanks again

 

I can't help with the fuel issue. But I can confirm that the OBDII tool you use makes a difference in clearing codes. I have a cheapo OBDII reader from Amazon. For the most part it works as advertised. But there was a code (don't recall the exact code but it related to OD lockup) that it simply would not clear. The dealer cleared it during a routine maintenance. I recently got the code again caused by my trans controller that came with my PacBrake. This time I had my Edge Insight Monitor which cleared the code with no issue.

 

The P0628 code is lift pump failure. The factory lift pump is directly connected to the ECM. There is no fuse in this circuit.
If the ECM does not see the expected voltage from the lift pump, it will set the P0628 code.

Your BD aftermarket lift pump likely uses a relay with a fuse that is plugged into the factory lift pump connector.
This setup will not set a code as the relay simulates the factory lift pump and the ECM sees no issue.

It sounds like your BD lift pump stopped which caused your truck to act up and set the lift pump code.
Reseating the wires and connectors to the lift pump corrected the issue.

Make sure all the connections are clean and secure and any splices are soldered not crimped.

 

"Make sure all the connections are clean and secure and any splices are soldered not crimped."
Darn! Why didn't I think of that at the time?
Thanks Stealth