2005 C0703 chassis code

[65comet]

I am not dyslexic and am reading the code correctly. C0703 Manufacturer Proprietary Code is what comes up on my laptop when I plug it in. Searched everywhere and can't get a definition for it. This code will go away and I then get codes for Fuel Rail Sensor Pressure out of range followed by Fuel Rail Sensor Pressure too high. But the funny thing is the pressure reading never gets above 0.2 PSI. Had a new fuel pump and FPDM a while back. A week ago I just got the Fuel Rail out of range error and replaced that sensor. A couple times going down the highway it would do nothing for 5 to 10 seconds, then come back strong. Now sitting in the driveway it will start with starting fluid, but no fuel pressure. I'm thinking the fuel relay is bad because I have no 12V power to the FPDM. And that maybe the C0703 is for something else that relay is suppose to power as well. Since those relays are a pain to get to, I wanted to see if anyone could find out what the C0703 is. European Corsca's use that code for suspension leveling system. I don't have air ride, but maybe something that is powered by that relay does a check to see if there is an air ride installed? Just grasping, Ford may not use that code in that way.

 

[65comet]

I cleared the codes and did some additional work. Now I got a C0704. Anyone know what either code is for? They don't show on any DTC list that I can find for Ford.

 

[1stGeExpedition]

Actron doesn't even show a C0703 or C0704 either. They do have the P0703 (brake switch B input circuit) & P0704 (clutch switch input circuit)

I found these for the rear suspension...
C1703
Right Rear Sensor Circuit Failure
C1704
Right Rear Sensor Circuit Fault



1 2 3 4 5

1st digit
P = powertrain
B = Body
C = Chassis

2nd digit
0 = Standard
1 = Manufacturer specific

3rd digit
1 = Emission management
2 = Injector circuit
3 = Ignition
4 = Auxiliary emission
5 = Vehicle speed & idle control
6 = Computer & output circuit
7 = Transmission

Based upon it saying it's manufacture specific I'm guessing they are C1703/C1704. I would have a Ford dealer scan it or just call them and ask what those C0703/C0704 codes mean.

I'm stumped as well. I tried bud lol.



Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[bedrck46]

If your not getting 12 V to the FPDM check the following fuses #28 and #12 If they are good then check to see if you have 12V at the Fuel Shut Off Switch. If fuses are good but no voltage at the cut off switch then I would say the fuel relay is the cause of the problem. That relay is not normally user serviceable as it is part of the circuit board in the fuse panel
check these links for some idea about the fuel relay
http://www.expeditionforum.com/f41/05-expedition-cranks-but-doesnt-start-21903/#post175219

http://www.expeditionforum.com/f41/po430-code-non-start-issue-22423/#post180859

 

[1stGeExpedition]

Oh and if interior fuse #12 is blown I'd suspect the Fuel Pump Driver Module is damaged or shorted out and needs replaced. You would have a P1233 code if you scan with a scan tool if this was the case. I highly doubt a new one could go bad that quickly but who knows.

Was the #12 fuse checked when the FPDM was replaced?





Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[65comet]

No power at shutoff switch. Fuses are good. So I'm going to tackle the fuel relay.

 

[bedrck46]

when you take the fuse block apart look for any burn marks on the board also look for any bad solder connections

 

[65comet]

Here's the fixes for mine

I took the fuse panel apart. One of the, I guess you'd call it connecting arms, that goes from a large relay on the front to a wire plug on the back had popped out of the two plastic tabs that are melted over to hold it in place. So it was making contact with another arm/bar that goes to a large relay slot that is empty. Fixed that by using a soldering iron to re-melt the plastic tabs.
Put it back together and still no fuel pump. But now there was power to the what is labeled as dark green with yellow strip wire coming out the top center connector in the bottom left hole. (It is really a medium green in my opinion. )
Have power to the inertia shut off switch.
Power going into the FPDM but not out. Previous testing on this two year old module seemed ok.
Got a new one from the parts store to plug in as a test. They said I could return it if it didn't look like it had been used. Plugged it in and set it on the frame. Nothing. Left the key on and in getting out of the vehicle the FPDM slid off the frame and ****** on the wires, followed by that fantastic whirl of the pump.
It was the connector to the FPDM. With a small under-powered flashlight I previously couldn't see that, way in on the female part of the connector, it had melted and the plastic was covering the metal.
My previous testing with pushing in the probes had probably forced a connection.
I don't know if the fuse junction box issue caused the overheating or if it was the FPDM. So since my wife is the primary driver I swapped in the new one and keep the old for a spare.
I cleaned the connector as good as I could, but I'm going to swap it out as well as soon as I find a new one or a good used.
I'm going to drive it until that happens. Nothing worse than an angry wife on the side of the road in a dead vehicle.
Have no idea why it gave those C codes, but could have been the arm/bar shorting that did that. I never found out what those codes are either.