Fuel tank

[Tray Burge]

I have an 03 Ram, 5.7 and had to replace the fuel tank due to a cracked hose neck, no big deal, but my question is: After I picked it up it was on empty (no CE light on) and I filled it up, needle shot to full and the CE light came on when I started it? Code said it was a faulty "fuel monitoring unit", but the gauge works. So I drove it for a while and then the CE light goes out and hasn't come back on. Did the "monitoring unit" have to fill up with gas or something, any idea what went on?

 

[Redtruck-VA]

That is unusual I would think due to there is only the two wires for the pump and two wires for the fuel level indicator. The fuel empty icon is triggered within the gauge cluster by the voltage seen from the float switch. I have had my float stuck off the resistor track on the switch a couple of times while working on it. I have a modified fuel system and have been into it more than a few times. Be very careful with the float and position it so it won't get hung up on the tank wall. With the unit pulled out you can manually test the switch.

 

[HemiLonestar]

It shouldn't matter, but did you put in a bigger tank or the same size? 26, 34 and 35 gallon tanks were available that year.

 

[JPT]

It shouldn't matter, but did you put in a bigger tank or the same size? 26, 34 and 35 gallon tanks were available that year.

Are you sure these are the sizes? I have an '03 with a factory listed 36 gallon tank. (Short bed, long bed, 4.7. 4x4) I thought it was only 26 and 36.

Maybe it includes 2500 & 3500, but for sure there is a 36 gallon option.

 

[HemiLonestar]

I'll check the factory parts book when I get home, but I'm pretty sure because I was kicking around putting the bigger tank in for a while.

 

[Redtruck-VA]

I have a PCM in Red that is supposedly for a 34 gal tank and I see no difference using a 24 gal tank. There is also 34/35 gal tanks on Ram 2500/3500.

 

[JPT]

According to the 2003 FSM, there were 26 and 35 gallon options only (for all sizes/engine types). So I guess I have the 35 not 36...

 

[HemiLonestar]

I have a PCM in Red that is supposedly for a 34 gal tank and I see no difference using a 24 gal tank. There is also 34/35 gal tanks on Ram 2500/3500.

PCM doesn't really matter, it can be adjusted with DRBIII. All it does is affect your DTE on the EVIC.

 

[Redtruck-VA]

PCM doesn't really matter, it can be adjusted with DRBIII. All it does is affect your DTE on the EVIC.

What I find curious is that when identifying various PCM's they are identified by auto or manual trans, Emission standard (Fed, Calif, overseas) and fuel tank size (24, 34 and 35 gallon). Like I said the current PCM I'm using is listed for a 34 gal. But I don't see any issues using it with a 24 gallon tank. This raises the question if the tank size is adjustable using a scanner then why identify the individual tank sizes?

 

[HemiLonestar]

Got me bubba lol...I just found the menu and options for it