1995 Explorer-Fuel pump working fine all of a sudden! Electrical?

[Wyoguy222]

Okay, so I posted in this forum a few days ago about my fuel pump not working. Well ever since I tapped the gas tank a few days ago, it has ran like a champ. No problems starting it! I have driven about 200 miles since.

I pulled the check engine codes, doing the paperclip method and got these codes:

542-Fuel Pump Open-Bad Ground
543-Fuel Pump Monitor Circuit shows no power

So my question is, does this mean it is NOT the pump, but an electrical problem? Or does the computer throw these codes when the pump itself is bad? I have a trip coming up, 300 miles one way, and I don't want to get stuck along the way! Yikes!

Could the tapping of the gas tank maybe moved a wire back into place? I'm so confused! Any help would be awesome! Thanks everyone

 

[2000StreetRod]

fuel pump supply voltage

The PCM measures the output voltage of the fuel pump relay that goes to the inertia fuel shutoff switch. The PCM also measures the supply voltage from the PCM power relay. If there is no voltage at the fuel pump relay output it sets 543-Fuel Pump Monitor Circuit shows no power. I think that when the fuel pump relay output equals the PCM supply voltage the PCM assumes the fuel pump circuit is open and sets 542-Fuel Pump Open-Bad Ground. I suggest you swap the fuel pump relay to avoid the 543 condition. Tapping the fuel tank probably eliminated the 542 condition. I doubt the connector was loose. Its more likely the fuel pump internal electrical connection is unreliable due to wear which is corrected by replacing the pump.