PO231 Code,and PO603 code

jerry edwards · #1 Sat, September 11th, 2010, 04:18 PM

PO231 comes up with Secondary Fuel Pump Circuit Failure,and PO603 comes up with a back up for the second fuel pump.Since there is only one fuel pump,i checked into it and it was supposed to be a bad relay,is that possible?If it is possible,does anyone know where it is?

***907DAVE*** · #2 Sun, September 12th, 2010, 07:48 PM

P0603 is because of your chip - normal condition and there is no need to worry about it.

P0231 can be cause by many issues, but if the truck is still running (fuel pump works) the condition is intermittent.

A few possible causes are....

* FPM circuit is open or it is shorted to ground
* Fuel pump relay output circuit (VPWR) is open
* Fuel pump relay has failed (no output voltage)
* PCM has failed
* Inertia Switch open
* Fuse box (rusted from water intrusion)

jerry edwards · #3 Wed, September 15th, 2010, 08:57 PM

Thank You
I'll have to investigate these things and hope to figure out which one it is.

jerry edwards · #4 Wed, October 13th, 2010, 04:04 AM

As far as these problems,i cleared the codes,and my gas pedal went bad for the 4th time.I replaced it.The truck then ran fine,last weekend i put the Gryphon back into tow stage,to tow my 44ft box trailer to the track (about 8,000lbs) with 2002 F250 PowerStroke 4x4.Once it started missing and blew pure black smoke at about 750 EGT for about 30 seconds,with check engine light.About 3 miles later the light went out,no more problems with hills and EGT to 1250. I checked the codes when i got to the track,they came up 603 and 1211.I cleared them,going home with no trailer i brought the EGT to 850 the light came back on with no miss.Sunday i brought the trailer home the light came on but it still didn't miss,it still came up with the same codes.Any ideas?