My parents 2003 ford expedition will turn over and start, but shortly after the engine will stall as if there is a main fuse box issue . today we took out the main fuse box , nothing looked burnt or blown . took out all the fuses and placed them back in there rightful home . so other then replacing the main fuse box , what should we start with before replacing a 400$ main fuse box . also we already replaced fuel pimp and the fuel filter, and some vacuum hoses that appeared badly withered while having this issue , made the expedition work for one day . so what do you guys think? please help !!!! also the code we received was p0231, anything thoughts will help !! thank you

 

There is nothing in your post that indicates the problem is the "main fuse box".

 

well the code was p0231, so what do you think needs to be replaced ? ECM replys? or the pcm relay? any other ideas

 

could it be the ECM? or maybe the PCM ? or a fuel pump relay ?

 

Might be any number of things, including any of those items.. or none of them.

Is the DTC O0231 a "hard" or an "intermittent" code?

 

Moved to correct forum since this is not an (5.4L) specific issue. You should get even more help from this area.

 

Double check the relays on the main fuse box as shown on this write-up.
2003 Ford Expedition, No Run, No Fuel Pump Operation, Code P0231

 

The 2 problems that seem to come up often are the fuel pump relay and the fuel pump. It seems to me I would certainly start this troubleshooting at the Central Junction Box (CJB). The fuel pump relay can't be seen when looking at the box with the cover off. The relay is underneath, soldered to the circuit board and not easily replaced. The article Alloro referenced is a good place to start. From the 2003 wiring diagrams the fuel pump relay has 2 output leads, a 14 ga wire to the Inertia Fuel Shut-off switch and an 18 ga to the PCM. I think the 18 ga wire to the PCM is a feedback voltage the PCM monitors to set the P0231 code. The 14 ga DG/YE (connector C270k pin 3) wire can be connected to a 12v source to bypass the fuel pump relay to determine if the Inertia Fuel Shut-off switch and fuel pump are working properly - the engine should run. The article could have added a test of C270k pin 3 on the CJB side to see if 12v was getting thru the fuel pump relay.

The article describes how to change the CJB printed circuit to replace the fuel pump relay. I cringe at spending $400 for a board to replace a $5 relay. I've worked up a schematic for adding an external relay to replace the fuel pump relay. It's based on the wiring diagrams manual and another effort like this on the 2002 Excursion forum. I think it can be done with 2 in-line fuses, a solid state relay (no contacts) and 3 wires going into the CJB.

 

I have a 2003 Expedition. My problem today, & on a couple of previous occasions, it will not rank due to fuse box issues. It always seems to be with Relays 1-6 & Relays 201-203. The power engages on the dash instruments briefly and then a clicking sound starts from the fuse box on interior passenger side. It's happened enough that I carry spares in the glove box. Even after I pulled all the mentioned above fuses the clicking continued until I turned the key back over. I reinserted all the fuses and it doesn't turn over at all. Where you insert the fuse in Relay 203 one hole looks a bit wider and melted. Once I had to replace a fuse/relay under the hood as well. I NEED DIRECTION please! I'm a way better cowgirl with my ranch than a mechanic! Thank you for any input you might have.

 

fuse box is tricky I went to junkyard got a 2004 fuse relay going to sauder on my 2003 ford expedition will that work part numbers are the same just 2004 does not have a dash will this work

 

Might as well replace the fuse box and fix it right. It's a plug-n-play deal, just disconnect your battery's ground cable before you start. The whole job takes about 30 minutes. The new fuse box comes with all new relays and fuses installed.


-Mike


Here's a link to buy a replacement fuse box from Tasca:
2003 Expedition Fuse Box from Tasca Parts ..... Ford P/N 3l1z14a068aa

 

im not sure how to reply to this forum. Sorry I’m interested in learning how to bypass the relay. We’ve replaced fuel pump and then ended up replacing fuse box but that only lasted a short time, couple weeks tops. Also my battery is being drained when trying to start it up it’s acting like it’s out of gas cranks cranks then slowly drained on batter. Alternator is good so is the fuel pump obviously. Months ago it was the smell of burnt plastic that caused us to replace the box this time no burnt plastic. Or blown fuses(visually) but loss of power then crank but no start please help

 

If you mean that you want to start a new thread of your own the click the "+New Thread" orange button near the top left of the forum page. You can also click this link: Ford Truck Enthusiasts Forums - Post New Thread (ford-trucks.com)