Fuel Sensor Oddity

[swexlin]

Hello all. So, last night I started my truck, got a "ding" CEL stayed on, and a message "fuel sensor fail". Gauge went to empty (I had about 3/4 tank). I restarted a couple times, and gauge registered again, but CEL stays on.

I got gas this morning, and gauge went to full - so it sees to be working. As a side effect, the CEL is still on, and seems to have partially disabled Remote Start. Truck will remote start, but will shut back of after about 10 seconds, with the message on the dash - "remote start disabled", start truck to reset.

I'm sure it's the CEL that's doing it. Before I go to Pep Boys and have them read the code, anyone experienced this?

 

[Hemi395]

That's most likely the fuel tank level sending unit going bad or getting gummed up. Try running a tankfull or 2 of Techron Concentrate Plus, that's said to clean the contact sweep on the sending unit...

 

[swexlin]

That's most likely the fuel tank level sending unit going bad or getting gummed up. Try running a tankfull or 2 of Techron Concentrate Plus, that's said to clean the contact sweep on the sending unit...

Thank you sir.

 

[ram1500rsm]

Yes, do a search. It's only a matter of time before your fuel sensor says goodbye. Depending on the truck mileage it'll make sense to replace the entire fuel pump. The work of getting to the fuel sensor or the pump will be the same. Replacing the fuel pump requires less time since you or the shop will directly swap the part. Taking a guess your truck has 55-65k Miles?

 

[swexlin]

Almost 47,000 miles.

 

[ram1500rsm]

Cell code will be p0463. You can try fuel cleaners and all that stuff. The cell will go away on its own but it'll come back later on. It'll be a slow dance initially then you'll start getting the cell more often until the sensor fully fails. Been there done that.

 

[Tim Garceau]

Whatever you do, do not replace with an OEM assembly or sender.

Ethanol Free gas will buy you some more time CEL free, but the damage to the continuity in the resistance reading of the sender has already been done.

 

[Wild one]

Whatever you do, do not replace with an OEM assembly or sender.

Ethanol Free gas will buy you some more time CEL free, but the damage to the continuity in the resistance reading of the sender has already been done.

Don't tell us that Tim,give us something to replace it with,that's better then the OEM unit.I hate guys that say don't use OEM parts,but then don't give anything that's better,so tell us what pump assembly you think is better

 

[swexlin]

Thanks folks. I trust my service tech at my dealer - dealt with him for years, and takes care of the Ram and the Viper. If the sender takes a complete dump, I'll deal with it then. I use my trip odo anyway when I get gas - I kinda know how much is in the tank.

What causes these to take crap? Bad batch of gas, or just cheap, or both?

 

[Tim Garceau]

I don’t have a lot of research on the sending units, but the rate of failure from the forums and YT is absurd where people are basically leaving the dealership and the next OEM replacement unit fails.

I bought a Maxfavor $75 entire assembly on amazon. Pump included flows 70-80GPH @ 55-65 psi. Have not found data on the OEM 5.7 unit, if it’s the same as a V6 it flows 60-70 and a ****** is 255LPH.

With an ohm meter on the failed unit, the mechanical sender assembly loses continuity initially(too much horizontal movement) in the middle and continues to grow over time until full/just before empty. The new sender is more robust in that mechanism, but with any aftermarket item time will tell it’s longevity.

 

[swexlin]

Thank you. That's a detailed explanation.

 

[Wild one]

I don’t have a lot of research on the sending units, but the rate of failure from the forums and YT is absurd where people are basically leaving the dealership and the next OEM replacement unit fails.

I bought a Maxfavor $75 entire assembly on amazon. Pump included flows 70-80GPH @ 55-65 psi. Have not found data on the OEM 5.7 unit, if it’s the same as a V6 it flows 60-70 and a ****** is 255LPH.

With an ohm meter on the failed unit, the mechanical sender assembly loses continuity initially(too much horizontal movement) in the middle and continues to grow over time until full/just before empty. The new sender is more robust in that mechanism, but with any aftermarket item time will tell it’s longevity.

View attachment 192313

View attachment 192315

I've never stumbled into the GPH of the stock pump,but it flows enough to supply a 150 shot of nitrous for a lot of guys,so the OEM pump itself isn't all that bad,the sensor though does leave a bit to be desired. The sensor won't affect the way the truck runs though,as mine has been tripping a cel for years like clockwork as soon as the Evic says 110 miles to empty,fill it up,clear the code and it's good to go till the next time it gets to 110 miles to empty,which is pretty well every week-end in the summer,as I hit the dragstrip usually with between 100 to 130 miles to empty,lol

 

[Tim Garceau]

Yeah I’d been nursing it for a year, recently when it was 90 percent of the range failing got tired of no remote start on cold days. Anyone that uses MDS, the CEL will not not allow it to activate.

Might eventually entertain a 100-150 progressive hit on E85 so wanted a little bit of headroom. Or like my last build, run into a used twin screw kit for low boost application.

 

[RedSRT4Me]

Whatever you do, do not replace with an OEM assembly or sender.

Ethanol Free gas will buy you some more time CEL free, but the damage to the continuity in the resistance reading of the sender has already been done.

I'm not trying to jinx myself but I replaced mine at around 57-58k. I replaced the oem unit with another oem unit. Im at 91k now still gtg

 

[OCDTech]

I'm not trying to jinx myself but I replaced mine at around 57-58k. I replaced the oem unit with another oem unit. Im at 91k now still gtg

Whole unit or just the sensor?

 

[PoMansRam]

I've not really heard of too many actual fuel pump failures on Ram pickups, just the ridiculously stupid fuel level sensor itself.

The problem is the printed circuit contacts (the semi-circular shaped board) erode away so that the wiper arm attached to the float no longer makes contact.

Is it the fuel we use? It it just your typically shiddy build quality? Like said above, it seems to hit you aroud the 3-4yr / ~45K mile mark.

I'd be leery of no-name Chinese FSUs given the issues I've had with them in the past, but like any aftermarket parts, they're all hit/miss.

Sometimes an aftermarket part is the same as the OEM part.

 

[Hemi395]

Well, sounds like I'm overdue for this lol. My trucks 7 years old and just hit 62K yesterday....

 

[TheEnder]

Well, sounds like I'm overdue for this lol. My trucks 7 years old and just hit 62K yesterday....

7 years old and you just hit 62K? shiiiiieeet!


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[OCDTech]

7 years old and you just hit 62K? shiiiiieeet!


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I average little under 5000yr on mine.


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[RedSRT4Me]

Whole unit or just the sensor?

Just the sensor. $110 for the part