Gas warning light?

Anyone want to tell me why the GAS warning light comes on at only 15 gallons used. According to my owners manual, my 2004 jeep liberty sport has a 19.5 gallon tank. Gas light comes on at 15 gallons, WHY!??! The damn thing can go another 60-100 miles easily.

DUH...so stupid people have enough time to find a gas station, I have stopped and helped two people now in Libertys that have ran out of GAS! Well actually 8 or 9 people total in different vehicles, but all the same, The warning light came on, it dinged etc and they kept driving ! I guess hoping the gas in there would reproduce or something LOL

04liberty4x4 said:

Anyone want to tell me why the GAS warning light comes on at only 15 gallons used. According to my owners manual, my 2004 jeep liberty sport has a 19.5 gallon tank. Gas light comes on at 15 gallons, WHY!??! The damn thing can go another 60-100 miles easily.

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Would like the warning when you're down to your last pint?

I ran out of gas once, it was on my way to work, but luckily it was right next to a gas station. After that, I always put some gas in after the warning light goes off, within 20-30 miles.

ild like mine when it gets to the last 1/4 cup.

then ild add a pinch of cinnamon, a touch of salt and a cup of whole milk. then ild pull over and get fat watching that hot lady with the cooking show. rachel ray maybe?

I never,ever let my KJ get below a 1/2 tank,mostly it never gets below 3/4 of tank.

Running a fuel injected vehicle under 1/4 tank of gas all the time will lead to early fuel pump failure and premature fuel filter plugging.Under 1/4 tank of gas the fuel pump is no longer sumurged in gas and that gas is what cools your fuel pump.

tjkj2002 said:

I never,ever let my KJ get below a 1/2 tank,mostly it never gets below 3/4 of tank.

Running a fuel injected vehicle under 1/4 tank of gas all the time will lead to early fuel pump failure and premature fuel filter plugging.Under 1/4 tank of gas the fuel pump is no longer sumurged in gas and that gas is what cools your fuel pump.

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I never knew that. I did hear it was bad to let your gas tank go less than half full in the winter to minimize condensation/water in your tank. TJKJ you should seriously think about writing a book called "Useful tips for running your 4x4".

tjkj2002 said:

Running a fuel injected vehicle under 1/4 tank of gas all the time will lead to early fuel pump failure and premature fuel filter plugging.Under 1/4 tank of gas the fuel pump is no longer sumurged in gas and that gas is what cools your fuel pump.

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Yup, had this happen to me personally some years ago and that's what I was told, and since then as soon as mine hits 1/2 tank I fill up.

I can see the gauge and I'm not waiting for some ding **** to tell me I need gas.

Dave

i did not kno that..

tjkj2002 said:

I never,ever let my KJ get below a 1/2 tank,mostly it never gets below 3/4 of tank.

Running a fuel injected vehicle under 1/4 tank of gas all the time will lead to early fuel pump failure and premature fuel filter plugging.Under 1/4 tank of gas the fuel pump is no longer sumurged in gas and that gas is what cools your fuel pump.

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What kind of mileage did you say you got? Wasn't it like 8 mpg? I wouldn't let it get below 1/2 a tank either.

Good to know about the fuel pumps, never heard that before. The filters can clog up the lower you run your tank because you'll be sucking all the junk off the bottom of your tank. The pump doesn't necessarily have to be submerged, it just has to have liquid running through it to cool it, although being submerged would cool it better. By the time the liquid stops flowing, the least of your concerns would be burning up the fuel pump, cause you'd be hitch hiking.

The EVIC mirrors the light... I've had the light come on a handful of times since owning my KJ, and the EVIC generally reports about 15 miles remaining. On one occasion, I drove for about 20 miles with the EVIC reporting 0 miles left... I'm not proud of that, and I know its not the right thing to do, but it lends credence to the "Alert early and panic the driver" mentality.....

-Blu

my dingger does not come on until i have 1 gallon left.
05 with 20.5 gallon tank.
I am sure that it is broken, but I don't really want to mess with it until it completely goes out.
I usually know how much I can get out of a tank by filling up at roughly 300 miles.

flair1111 said:

ild like mine when it gets to the last 1/4 cup.

then ild add a pinch of cinnamon, a touch of salt and a cup of whole milk. then ild pull over and get fat watching that hot lady with the cooking show. rachel ray maybe?

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Only 1 mistake. It would be "about a cup". Rachel would make running out of gas a
fun thing to do!

Terry

Light

Here's the quote from the 2004 service manual:

"Each time the cluster receives messages from the PCM indicating the percent tank full is less than 15, the gauge needle is moved to below the one-eighth position on the gauge scale and the low fuel indicator is illuminated. The low fuel indicator remains illuminated until the cluster receives messages from the PCM indicating that the percent tank full is greater than 15 (one-eighth), or until the ignition switch is turned to the Off position, whichever occurs first."

So the service manual seems to be at odds withitself over exactly when the light comes on, either at 12.5% or 15%. I don't know how accurate the PCM's readings are, but it's probably not accurate enough that either number would matter.

12.5% of 19.5 gallons = 2.4375 gallons remaining.
15.0% of 19.5 gallons = 2.9250 gallons remaining.

So let's assume the worst case scenario, city driving. I'm averaging 16.7 mpg in the city, and assuming the 12.5% number, I can go 40.7 miles before empty. My light usually comes on when the EVIC reads approximately 40 miles to empty.

But I think there is still some idiot proofing built into the system. I usually try to drive 40 miles past when the EVIC reads '0 miles to Empty'. I pushed it to 60 miles past empty once (I had a gas can with me), and I started sputtering, and happened to be passing a gas station and pulled in. I ended up putting 18.9 gallons in, which still meant I had 0.6 gallons left. I could have driven another 10 miles (in theory, assuming the fuel pump is able to pump 100% of the fuel out of the tank)!

This built in idiot proofing may go back to what TJKJ said about burning up the fuel pump at low volumes.

I hate how EVERYTHING, has to be built to function for the dumbest individual. Build it for the average man, and force the stupid people to adapt, learn, do without, or die.

Mine def comes on at 15 gallons.

It's done it 3 times on the way to get gas


First time I filled 15.3 gallons

Next two times were 15.2 and 15.236 gallons


I just find it odd that it comes on with 4.5 gallons left, all my honda's usually come on when dead empty with 1.1 gallons left in reserve.

Mine comes on when "Miles to Empty" reaches 23.

I've never seen mine. It never gets that low

I always fill at ~1/2 tank too. The closest I've ever come to running out of gas in my KJ is getting down to ~1/4 tank.

Why chance it? In this region, that's just too dang risky. Winter especially. That's how I look at it. Gotta fill up sooner or later, why not keep it on the full side?

We find that if we run our tank below half , the KJ doesn't run as well and lacks performance.

04liberty4x4 said:

Mine def comes on at 15 gallons.

It's done it 3 times on the way to get gas


First time I filled 15.3 gallons

Next two times were 15.2 and 15.236 gallons


I just find it odd that it comes on with 4.5 gallons left, all my honda's usually come on when dead empty with 1.1 gallons left in reserve.

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Ditto on mine.

And in fact, I have a major confession to make.

For some reason, until this thread, I had it burned indelibly into my brain, that the '04 had a 16.5 gallon tank, and had always wondered why the fuel light came on when there was only 1.5 gallons left. I always felt that was a little close to the bone-- even though the fuel light has never been something I rely on, I simply look at the gauge. But what's interesting is that shortly after my fuel light comes on, the gauge is pretty much on empty.

Meaning, that if my gauge was on E, and it comes on at 15 gallons, I could go a significant distance before running out. There have been at least two occasions where I left the house when the fuel light was already on, got distracted and and suddenly realized I was on empty. I was sweating bullets as I went looking for a gas station (there are places in Seattle where they literally don't exist, believe it or not) thinking I had a 1/2 gallon left. And at 16mpg in town, I was under the impression I was running on fumes.