So it will run on juice but the pump isn't coming on. Try this, find fuse 20, apply battery power to it's terminals, does the pump come on and the truck run? Yes - wiring to pump and pump are not the problem as that bypasses the relay. Doesn't run? Go try power at the pump itself. (These days I don't trust any parts without testing them first as so many are bad) Now if it runs we need to check the control side of the system, That is in the powertrain module which then turns on the pump relay. If the PCM was replaced to correct this and it didn't so they replaced the pump with no results then we need to test the wiring, from the power to the grounds. Applying power at the fuse would test the power side wiring from the fuse box to the pump. The relay is part of the fuse box so testing it isn't that fun, the easiest way is with a scan tool that can activate the relay, then you can use the wiring diagram to test each wire.
Monday, December 8th, 2025 AT 11:57 AM
