2nd Gen Non-Engine/Transmission lift pump

[Peter Thorp]

2001 Ram lift pump is failing to receive a signal from ECM to turn on. Replaced ECM and no change. Does ECM receive additional data from a pressure switch, possible in injection pump?

 

[hcole]

No, it should turn on for a 1/2 second or so on the ignition switch turned to on. Then if you bump the starter, it should run for app. 20 seconds. There is no pressure switch or other signal other than what i said. After the engine is running, the fuel pump will run as long as the engine does without any shutoffs or slow downs regardless of pressure, need or fuel use.

 

[ARARAR]

I believe there is a fuel pressure solenoid the starts and stops pressurization at start-up. You might look into that.