I was driving along and truck died.would not restart.Cannot get trouble codes as scan tool is unable to connect. No sensor ground in DLC. Voltage at the pump lead connection is 9.5 . Can crank sensor affect pump Circuit? Can not figure out why there is only 9.5 volts at connection which is probably too little to operate pump under a load.

 

Lift pump working?

 

Edit: Cummins* you can spell check by looking the badge on your truck
Should get 12+ volts there running or not.
Find the electrical problem and/or replace lift pump.
Get an AirDog or the like, and fuel psi gauge if you like your VP44

Symptom:
P0628-LOW VOLTAGE DETECTED AT THE FUEL LIFT PUMP
When Monitored and Set Condition:
P0628-LOW VOLTAGE DETECTED AT THE FUEL LIFT PUMP
When Monitored: While the key is on.
Set Condition: The voltage detected on the Fuel Lift Pump is above a calibrated value for
a calibrated amount on time.

POSSIBLE CAUSES
LOOSE CONNECTION
LIFT PUMP SHORTED TO VOLTAGE
RETURN CIRCUIT OPEN
LIFT PUMP
ECM
TEST ACTION APPLICABILITY

1 With the DRBIIIt, in system test actuate the lift pump.
Does the lift pump run?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Go To 2
No ! Test Complete.

2 Lift pump actuation still running.
While the lift pump is running, wiggle the wiring harness and connectors throughout
the circuit.
Does this interrupt the pump operation?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Repair the loose connection.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 3

3 Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the lift pump supply circuit between the ECM harness
connector and the lift pump harness connector.
Is the resistance less than 1 Ohms?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Go To 4
No ! Test Complete.
188
DRIVEABILITY - DIESEL

4 Measure the resistance of the return circuit between the lift pump connector and
battery negative.
Is the resistance less than 1 Ohms?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Go To 5
No ! Repair the open circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

5 Measure the voltage between the supply and return circuits of the lift pump
connector.
Is the voltage greater than 1 volt?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Repair the lift pump circuits shorted to voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Go To 6

6 Reconnect the ECM harness connectors.
Connect a jumper wire between the supply and return circuits of the lift pump
harness connector.
Turn the ignition on.
With the DRBIIIt, read DTCs.
Did DTC P0628 set?
ENGINE- 5.9L
CUMMINS 24V
DIESEL
Yes ! Replace the lift pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
No ! Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).

 

I repaired DLC by temping anewground to sensor ground pin and was able to get codes out .Codes were 234 237 1689 and 1698. I then replaced the original lift pump and filter with new ones.Pump now operates,when I tried to start it I now have fuel to filter. where I bled it. I ended up losing my drb connection so I can not get any codes or check if old codes still exist.I checked the DLC grounds and both are good as is the battery supply ,Scanner is still unable to connect. I am convinced there is an electrical problem somewhere. If crank sensoris bad would I be getting fuel ?