Hello all,
I’m having a fuel pump issue with my 1992 F150, 4.9 i6 with 139000 miles. Everything was working perfectly fine until I changed out the broken lcd odometer display. Now the fuel pump won’t turn on, and my fuel gauge is pegged well over the full mark. Jumped out the service port and got a 542 code. Which looking online says it could be the fuel pump or anywhere in the wiring between the pump and the ECU. I checked the inertia kill switch and it’s all good. I’ve switched around relays, and even jumped out the fuel pump relay. I just want to check to see if there is anything I could have messed up by changing the display, or that I missed troubleshooting before I attempt to drop the tank and replace the fuel pump? I should mention the truck sat with the positive batter cable disconnected for about a month while I waited for the dash parts to come in.
Had to buy a Chilton manual for a wiring diagram.… $30 V8 moment 🤦🏻♂️. Our truck only has one fuel tank. When I put the instrument cluster back in, I must not have clipped the fuel tank selector jumper back in all the way. 🤣🤣🤣
It’s always the simplest things.
It's an electrical issue. Code 542 means that the computer is seeing more resistance in the fuel pump circuit. Check the fuel pump relay. Make sure it's the relay-if it's not, then you may need a new fuel pump.
Thanks! Just wanted to make sure.