2nd Gen Non-Engine/Transmission "Low Fuel Light"

[ROCK KRIES]

fuel guage

That makes sense. I will check closly the next few fill and make sure DTE moves and low light is correct. I did fill to the top to see how much it took.

rock

 

[B.G. Smith]

The DTE figure is calculated by how much the fuel gage says is left in the tank multiplied by the average miles per gallon of the current reading on the overhead console so don't depend too much on it being extremely accurate. The consensus is that there is about 7 gallons left in the tank when the light comes on, as stated numerous times above, that is probably a good cushion as the fuel returning from the VP is heating what is left in the tank plus the level has to be getting pretty thin on the bottom of the tank. As far as the lift pump working harder??? the output pressure will be reduced by the amount of suction pressure that it loses by the lower fuel level, probably not detectable on a standard gage. bg

 

[terrywerm]

Mine comes on at 1/8 of a tank. If I fill up then it only takes 20 to 22 gallons, but it varies a bit. Usually I refill about the time I hit 1/4 tank, but a few weeks back I drove 30 miles or so after it came on, pulling the TT across Nebraska in the middle of the night. Still only took 26 gallons to fill it then, and it was definitely headed for the big 'E'.

 

[BigIronRam]

I guess mine's weird. It comes on at 600 miles, just like clockwork, shows 1/8 tank of fuel, takes ~34 gallons everytime. I figure mine means, take this exit and buy fuel now! :-laf



Robert

 

[ntillm01]

I guess mine's weird. It comes on at 600 miles, just like clockwork, shows 1/8 tank of fuel, takes ~34 gallons everytime. I figure mine means, take this exit and buy fuel now! :-laf



Robert

I wonder if your float arm isn't bent. If it's showing 1/8 tank and you've only got a gallon or so left... the float to sensor correlation is way different than most. Sounds like you kinda like it that way, though.

 

[MRose]

So how big is a 99' SWB quad/extended cab? I've run it down to 0 on the DTE and it takes about 25g. Is it bigger and my gauge is bad?

 

[ROCK KRIES]

Yours should also be 35 gallons. The fuel guages suck. My truck has sat a total of 5 days twice to fix the problem. Still goes over full and at 1/8 takes 25 gal.

 

[Thomas]

So how big is a 99' SWB quad/extended cab? I've run it down to 0 on the DTE and it takes about 25g. Is it bigger and my gauge is bad?

From the 1999 Ram Pickup slick sales brochure:

Fuel Tank - 26-gallon on 1500 short bed, 34-gallon on 2500 Club Cab™ and Quad Cab™ short bed, and 35-gallon on all long-bed models

A careful reading of TSB 14-01-00 at http://dodgeram. info/tsb/2000/14-01-00.htm should convince you that your 1999 SWB Ram 2500 uses P/N 52102238AG Tank, Fuel, Diesel Engines. P/N 52102238AG is a 34-gallon tank.

Unless your truck has been modified, I think you'll find you have a 34-gallon tank, just like all second generation short-bed Ram 2500's.

 

[MRose]

So does the trip computer, when full, assume you have 34g or does it compute DTE by the gauge? Oh wait, just answered my own question. If I get the computer to 0 on the DTE then it must read the gauge to figure it out. So where does it get its values to compute mileage? When at half tank (gauge) does it assume you burned 17g to get to your current mileage or does it know that I've burned more like 12. 5g using a computer computation of number or injector cycles and APPS?

 

[B.G. Smith]

So does the trip computer, when full, assume you have 34g or does it compute DTE by the gauge? Oh wait, just answered my own question. If I get the computer to 0 on the DTE then it must read the gauge to figure it out. So where does it get its values to compute mileage? When at half tank (gauge) does it assume you burned 17g to get to your current mileage or does it know that I've burned more like 12. 5g using a computer computation of number or injector cycles and APPS?

The computation, if you can stretch the imagination and call it that, seems to be pretty simple. The gage, if it were accurate, would indicate 34 or 35 gallons when full, 17. or 17. 5 gallons at half and somewhere around 8. 5 gallons at 1/4 tank. It has to have a mpg figure to give the DTE mileage so it uses the figure on the overhead console which is an average of the mileage since the last time the mpg was reset. If your gage is dead on and you drive exactly the same all the time it might be pretty accurate. bg

 

[.44 mag]

Fuel Light = Lift pump



I'm more than a little gun-shy right now. I normally never get the tank low enough to make the light come on. After taking a recent trip and having the light come on a few times over the course, my "check engine" light popped up. It seems that my lift pump took a dump and ultimately wiped out my VP44.



Don't know for sure if the tank running low killed it, but I see a bigger tank in this truck's future.