As far as I know, there is no code for a faulty lift pump.
Check first to see if the lift pump is connected to the lift pump wiring connector.
If you can find this: https://www.dieselplace.com/forum/63-...ml#post6910025
, apply 12v and open the water in fuel drain by the thermostat. Make sure to have a container to capture fuel. If you get a steady stream of fuel the lift pump is working.
If the lift pump works, then there is a problem with the lift pump relay or another electrical short.