Replace PCM fuel gauge not working

Redrooster · Jul 27, 2022

I have a fuel gauge not working on my daughters 2005 ford sport trac 2WD xls. My father in law did some work on it before delivering it to North Carolina from Florida. It has a new dash gauge cluster unit. He checked all the fuses. He got a new fuel pump and sending unit, plugged it in out side of the truck and tried adjusting the float, no change. When he delivered it I rechecked the fuses. Did a system gauge check. The fuel gauge comes to E then goes all they way to full then back to e. When the system check is done the gauge falls below e. I got a scanner and it said the fuel circuit a failed. I then found a large resistance between the dash cluster and fuel sending unit connection. I broke part the yellow/white fuel sending wire at the dash cluster, at the fire wall, at the fuel pump connection, and at the pcm. Of course I did the pcm last and that removed the high resistance. At this point the technical for troubleshooting guide that I could find for free (deal with a tsb for something related to fuel gauge) said replace pcm. The pin that sends the fuel signal ref voltage was reading 500k ohms to ground with nothing attached. Another code that read out on the code reader was “ key not switch on” something like that (didn’t write it down).

Anyway I have everything back together and the truck drives. It just beeps every 15 minutes and says low fuel. The gas reads below E. But I showed my daughter how to rest the trip meter and said to fill up every 250miles.

What I am looking for is any reputable pcm vendors that I can get one from with two keys preferably (I have seen fs1inc.com for $616) and (a posting on eBay from theecuconnection $267).
Both vendors ask for the vin and verification of the ecu prior to shipping unit. We only got one key with the purchase. I am also open to any suggestions or ideas on if you think this is not a pcm issue.

Thanks in advance,

Red Rooster

Todd Z · Aug 1, 2022

Have you swapped the anti slosh module on the back of the dash ??? Not commonly known its back there...

Redrooster · Aug 1, 2022

Does the 2004 and 2005 have a separate anti slosh module (i looked and didn't see one, but didn't tear apart the back of the cluster)? When I had the dash cluster out there are two connectors on the back that appeared to be all one circuit board. My father in law got the a repaired dash cluster through his mechanic, who is reputable and trusted, I will try and get more details on where exactly he bought the cluster though. I really think it has to do with the PCM though since all the high resistances go away as soon as you unplug the PCM.

Todd Z · Aug 2, 2022

It might. But with the stupid electronic dashboard anything is possible. It might be worth resending it back to circuit board medics and see if they can refix the instrument cluster because it sounds like I just wasn’t fixed right.

curtis james · Aug 2, 2022

on my 04 it had some different fuse locations then my 05, but if fuse locations are different then maybe the wiring could be off if cluster is from a 04 or depending on month manufactured it could be off. people call it different jobs, my 09 ford flex oil filter has different threads from what month it was produced, did your dad replace cluster for the same reason with gauge, if not then sounds like cluster or pinched wire under truck from sending unit, have some one watch gauge while ya wiggle wires or plugs to see if it moves. the truck looks amazing by the way.