Hi Everyone, thank you for reading my post. I have a 1998 Ford F150 with a 5.4 liter engine. 3 months ago, I replaced the intake gaskets and spark plugs and a couple of coil over packs, and the truck ran beautiful.

A couple of weeks ago, the truck did not start one morning. I cannot hear the fuel pump kick on when key is turned. I have no power at the pump. Fuses and relays are good. The fuel pump is new, like yesterday, lol. I plugged my snap on scanner in and I come up with a P0231 - Fuel Pump Secondary Circuit Low code. Does this truck have a fuel shutoff switch? Also, where abouts is the interia switch located? If anyone else has had this problem, assistance would be appreciated.

Thanks, David

 

Moved from 2011 F100 forum.

Welcome and thanks for joining us at FTE!

 

this DTC indicates a fuel pump secondary circut failure, if engine starts replace pcm. if not,
check B+ to fuel pump relay
turn ign. off disconnect fuel pump relay measure voltage between B+ terminal at fuel pump relay harness connector and ground if voltage is less than 10.5 check fuses fuse links and shorts to ground
if more than 10.5 measure resistance between FP PWR terminal at fuel pump harness connector and negative battery terminal if resistance is less than 10 ohms replace fuel pump relay. if resistance is more repair open in FP PWR circut.

hope i could be of some help
good luck in figuring it out

 

Allrighty then, what I have is.............

The inertia switch is fine. I pulled the fuel pump relay, plugged in my voltmeter, plugged in the positive lead to the battery terminal for the relay and hooked the negative lead to the ground on the battery and I have no voltage with the ignition turned off. I suspect I have a bad ground somewhere. Well, back to it, lol

 

Ok, what I did was provide direct current to the plug for the inertia switch, the circuit runs from this switch to the fuel pump. When I did, the fuel pump did kick on and I turned the key and the truck started. As soon as I disconnected the direct power, the truck stalled.

 

I finally pulled the power distribution box off, removed the back cover, exposing the wires underneath, the wire is broke that runs from the fuel pump fuse to the fuel pump relay, the wire broke off the terminal. That was "easy", lol