Low Fuel Level Warning

[Tommy Gun]

My low fuel level warning is driving me crazy!

It is now hitting me when my gauge shows me 1/2 tank.

It seems like it has gotten worse and worse over time.

I've cleared and reset everything all the time, but I think it's learning is all messed up.

Running around town I usually see about 9 to 11 mpg. :look:

At 1/2 tank it starts it's Low Fuel warnings. Then every 5 miles or so. :banghead:

I see no way listed in the manual to change it?

At just under 1/4 tank it tells me I have zero miles left and it seems like every mile then it is beeping. :nonono:

Wondering if disconnecting the battery for a while might reset it, but haven't tried that yet.

:banghead:


I have filled it all the way up a couple times now w/ no failsafe that I was getting before, but not sure if part of that may have been due to elevation?

.

[VaporDude]

I would take it to the dealer and let them deal with it. I don't think it will change when the battery is disconnected for a while. There may be some software update that needs to be installed.

[Tommy Gun]

I no longer have a dealer to take it to. :nonono:

.

[VaporDude]

I no longer have a dealer to take it to. :nonono:

.

That might be a problem. :doh2:

[onecrazydog]

Take it out on a good highway trip and drive normal... Should bring the averages up...

[Darkside]

So besides being slow, red cars get shite mileage too. That sucks.

Should have gotten a black car instead.

[Tommy Gun]

Take it out on a good highway trip and drive normal... Should bring the averages up...


I don't know anyone I trust to drive the car like that. :look:



.

[Tommy Gun]

So besides being slow, red cars get shite mileage too. That sucks.

Should have gotten a black car instead.



:hey2:

[VaporDude]

So besides being slow, red cars get shite mileage too. That sucks.

Should have gotten a black car instead.

When we were looking for a car, myy wife said any color but red. I asked her why not red. She said that they are to slow.








:haha:

[Alloy Dave]

Could it be a sending unit in the tank defective? That would be a bear to check I think....you may have to pull the tank. One thing that might be easier to check is to remove the wire from the sending unit and feed it voltage to see how the gauge reacts. I don't know what it's set for , but let's assume its 0-5V. Then run 5V to it and see what the gauge does...then try 2.5V. Not sure if this is even possible on this car...it may be a resistance type gauge instead of reading off voltage..would need some technical wiring diagrams.

[onecrazydog]

I don't know anyone I trust to drive the car like that. :look:



.

Don't let the tank get below 3/4's full then...

[Tommy Gun]

Don't let the tank get below 3/4's full then...


I like keeping the weight off the car when I go on the prowl. :weg:


LOL

[Tommy Gun]

Could it be a sending unit in the tank defective? That would be a bear to check I think....you may have to pull the tank. One thing that might be easier to check is to remove the wire from the sending unit and feed it voltage to see how the gauge reacts. I don't know what it's set for , but let's assume its 0-5V. Then run 5V to it and see what the gauge does...then try 2.5V. Not sure if this is even possible on this car...it may be a resistance type gauge instead of reading off voltage..would need some technical wiring diagrams.


I hate electrical stuff, that may be a last resort.

[Joe G]

I like keeping the weight off the car when I go on the prowl. :weg:


LOLIs that why you don't let Sharun in? :look:

[68fastback]

I wonder if this somehow has to do with the fact that it's a 'saddle' tank which means there must be some crossover tube since the pumps are on one side only ...is it possible the indicated fuel level is not correct and the side that the pumps are in is actually that low? Is it possible the crossover (howev er it's implemented) is not equalizing both sides of the tank somehow? That might also explain the filling problem if one side is filling but the fule is not equalizing to the other side? Not sure how the fuel balances so I'm just guessing based on the symptoms.

[Tommy Gun]

I'll pull the tank this weekend and un-weld it and check it out. :terrorist:

[Carnut]

I thought you had a complete service manual for your car?

What does it tell you?

[Birdman]

I'll pull the tank this weekend and un-weld it and check it out. :terrorist:


I assume you are talking about the GT500.

No need to pull the tank to check the sending unit. Just take the rear seat bottom out. The fuel pumps and sending unit are right there installed from the top. (disconnect Batt first) Then at the top of the tank just disconnect the wire connector, fuel and vent lines then push down and turn the large ring retainer that holds the assembly in place. Then you can remove the entire assembly. It might be the float is faulty, you might need a new sending unit..don't know how to determine that accurately though.

Section 310 in the 2007 Mustang workshop manual

[VaporDude]

If this is the Shelby, mine did this same thing over the winter. The battery went dead, I charged it up and I had about a half a tank but my distance to empty was at about 25 miles. After a few refilles and a few starts of the car, it went away and returned back to normal. Was your battery dead for an extended period of time?

[Boston Mike]

So besides being slow, red cars get shite mileage too. That sucks.

Should have gotten a black car instead.

:goodpost:

[Tommy Gun]

I assume you are talking about the GT500.

No need to pull the tank to check the sending unit. Just take the rear seat bottom out. The fuel pumps and sending unit are right there installed from the top. (disconnect Batt first) Then at the top of the tank just disconnect the wire connector, fuel and vent lines then push down and turn the large ring retainer that holds the assembly in place. Then you can remove the entire assembly. It might be the float is faulty, you might need a new sending unit..don't know how to determine that accurately though.

Section 310 in the 2007 Mustang workshop manual



My gauge works fine it's the info calculating center that is freaked out.


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[Tommy Gun]

If this is the Shelby, mine did this same thing over the winter. The battery went dead, I charged it up and I had about a half a tank but my distance to empty was at about 25 miles. After a few refilles and a few starts of the car, it went away and returned back to normal. Was your battery dead for an extended period of time?


No.


I'm thinking of clearing/resetting the info then disconnecting the battery for a day, then reconnecting and see if it changes.

[Carnut]

No.


I'm thinking of clearing/resetting the info then disconnecting the battery for a day, then reconnecting and see if it changes.

You could drain all the gas, measure it, then refill it. I think you have to do it about 12 times before it resets. BTW, you alternately connect the battery between fills and if you miscount you will have to start over again with new gas so be accurate.

[Tommy Gun]

You could drain all the gas, measure it, then refill it. I think you have to do it about 12 times before it resets. BTW, you alternately connect the battery between fills and if you miscount you will have to start over again with new gas so be accurate.


What the heck are you talking about squirrel breath????? :trouble:


.

[bigb427]

In order to test the fuel gauge and all its related components you will need a scan tool that can communicate with the IC module AND is active command mode capable. You also may need a variable resistor of at least 0 ohms to 160 ohms operating range.
A couple things that will make the gauge and DTE inaccurate are refilling the tank with the key on, and/or only putting in 4 gallons or less. If either of those were done disconnecting the battery for 10 minutes will reset the fuel gauge to normal operating strategy and make things accurate again.
Based on what you've said my guess is the instrument cluster is the problem, but diagnosing it over the internet leaves quite a bit to be desired. I would also recommend taking it to the dealer so you don't wind up replacing parts that aren't bad.

[Birdman]

In order to test the fuel gauge and all its related components you will need a scan tool that can communicate with the IC module AND is active command mode capable. You also may need a variable resistor of at least 0 ohms to 160 ohms operating range.
A couple things that will make the gauge and DTE inaccurate are refilling the tank with the key on, and/or only putting in 4 gallons or less. If either of those were done disconnecting the battery for 10 minutes will reset the fuel gauge to normal operating strategy and make things accurate again.
Based on what you've said my guess is the instrument cluster is the problem, but diagnosing it over the internet leaves quite a bit to be desired. I would also recommend taking it to the dealer so you don't wind up replacing parts that aren't bad.


Thanks for the info Big' very interesting and helpful....good insite to this issue. :tiphat2:

[Joe G]

Thanks for the info Big' very interesting and helpful....good insite to this issue. :tiphat2::iagree:

Rep points to him!

[Tommy Gun]

In order to test the fuel gauge and all its related components you will need a scan tool that can communicate with the IC module AND is active command mode capable. You also may need a variable resistor of at least 0 ohms to 160 ohms operating range.
A couple things that will make the gauge and DTE inaccurate are refilling the tank with the key on, and/or only putting in 4 gallons or less. If either of those were done disconnecting the battery for 10 minutes will reset the fuel gauge to normal operating strategy and make things accurate again.
Based on what you've said my guess is the instrument cluster is the problem, but diagnosing it over the internet leaves quite a bit to be desired. I would also recommend taking it to the dealer so you don't wind up replacing parts that aren't bad.



Actually this is very helpful.

I almost never fill the tank up.

All through the summer I just put in 4-5 gallons to get me around town.

I never filled it up because I was having issues w/ filling it and it is just extra weight I'm carrying around.

It was just near the end of summer when I tried filling it up a time or 2 to see how it reacted and didn't have an issue....except for the info center telling me I was low on fuel all the time.

I will try the battery disconnect and see if it improves.

Hopefully that will do it since I don't have access to the other things you speak of.

:tiphat2:

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[Birdman]

:waiting:

[bigb427]

In the Ford shop manual it states you must add at least 15% of the tanks capacity when refueling a Mustang. That equates to aprox. 2.5 gallons. You might be OK with 4 to 5 gallons, but I have found that in some cases on other model Fords it would be a problem. This is most likely due to a larger fuel tank. I tell people when refueling add at least 4 gallons just to play it safe.
You are probably ok, but of course it's easy to disconnect the battery and then fill the tank all the way to see if that remedies your concern. By all means go ahead and try this.

[Tommy Gun]

May be a little while, our weather forecast is for rain the next 7 days. :nonono:

.

[Tommy Gun]

Supposed to actually stop raining this weekend.

Haven't had the car out in weeks.

[Tommy Gun]

I had the GT500 battery disconnected all day, just hooking it back up now.

Gonna clear the info center, then in the morning fill it up and see what happens....


Should be out of gas by mid day. :look:

.

[Tommy Gun]

Maybe I should retry the clear stuff thingy again.

Went for a ride again today and the idle seems a little rough for some reason?

Mainly (I think) after some short WOT's.

Come to a stoplight and it feels rough a couple times?

Maybe it's just me or maybe as Jon Lund would say "...it's just probably bad gas..."

[Tommy Gun]

I usually drive it each weekend, although there was the 2 weeks we had all the rain a week ago...

[Birdman]

Maybe I should retry the clear stuff thingy again.

Went for a ride again today and the idle seems a little rough for some reason?

Mainly (I think) after some short WOT's.

Come to a stoplight and it feels rough a couple times?

Maybe it's just me or maybe as Jon Lund would say "...it's just probably bad gas..."


rough idle could be the plugs ..just sayin

[Tommy Gun]

I think the plugs only have a few thousand miles on them, if that?

[Birdman]

I think the plugs only have a few thousand miles on them, if that?


Depends on how many WOT runs are on them they could still be an issue, might be worth a check

[Tommy Gun]

Well you didn't say that.

I can't count the number of WOT's. :rofl3:



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[Birdman]

Well you didn't say that.

I can't count the number of WOT's. :rofl3:



.

I figured as much..:innocent:

[The Bone]

I put fuel stabilizer in my car when I park it in the winter

[Tommy Gun]

I still drive mine.

It usually doesn't get cold enough to not drive it once in a while.

I think Feb-March are the worst months, it may sit for 2 weeks sometimes.

I never put stabilizer in the car.

I keep hearing horror stories about how additives may harm some coating that is on the S/C rotors?

[Birdman]

I still drive mine.

It usually doesn't get cold enough to not drive it once in a while.

I think Feb-March are the worst months, it may sit for 2 weeks sometimes.

I never put stabilizer in the car.

I keep hearing horror stories about how additives may harm some coating that is on the S/C rotors?


Fuel does not go through the SC at all......only air...:shades:

[The Bone]

I use it in all my gas powered lawn tools and they start right up when winter is over with no ill effects

[Tommy Gun]

Fuel does not go through the SC at all......only air...:shades:


:oops: I must be thinking about carb/TB cleaner type stuff

[Tommy Gun]

Okay, I finally got down to about 1/8 of a tank w/ no Low Fuel Warning. :wtg:

I checked the info and it said I was 52 miles to empty.

Filled up and it took 13 gallons.

Gas at $3.47 :yay:


Good thing.....I averaged 10 miles to the gallon so far. :nonono:


.

[HSURB]

The low fuel level warning has never come on in my car. Confused.

HSURB®

[VaporDude]

Okay, I finally got down to about 1/8 of a tank w/ no Low Fuel Warning. :wtg:

I checked the info and it said I was 52 miles to empty.

Filled up and it took 13 gallons.

Gas at $3.47 :yay:


Good thing.....I averaged 10 miles to the gallon so far. :nonono:


.

I told you it would straighten itself out. Just have to let the computer recalculate everything.

[Tommy Gun]

In order to test the fuel gauge and all its related components you will need a scan tool that can communicate with the IC module AND is active command mode capable. You also may need a variable resistor of at least 0 ohms to 160 ohms operating range.
A couple things that will make the gauge and DTE inaccurate are refilling the tank with the key on, and/or only putting in 4 gallons or less. If either of those were done disconnecting the battery for 10 minutes will reset the fuel gauge to normal operating strategy and make things accurate again.
Based on what you've said my guess is the instrument cluster is the problem, but diagnosing it over the internet leaves quite a bit to be desired. I would also recommend taking it to the dealer so you don't wind up replacing parts that aren't bad.

I need to reset this again.

Time to disconnect the battery.

I've been putting 5-6 gallons in at a time, but I think it catches up on me because I'm not filling it up.

With 600 HP ricers running around, I don't want to be caught w/ a full tank of gas in this land barge. :wtg:

.

[onecrazydog]

I need to reset this again.

Time to disconnect the battery.

I've been putting 5-6 gallons in at a time, but I think it catches up on me because I'm not filling it up.

With 600 HP ricers running around, I don't want to be caught w/ a full tank of gas in this land barge. :wtg:

.


Full tank means more traction, less chance of fuel pump starvation too... Lose the weight upfront somewhere...

[Tommy Gun]

I forgot to disconnect the battery earlier, got involved in cooking dinner. :banghead:

You are correct about losing weight.

I plan on trying to lose whatever I can on the track car in the next couple months.

Don't really care about the GT500.

Just waiting for the cars value to skyrocket since Carroll passed. :waiting2:



:ohsnap:

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[Tommy Gun]

Man this thing acts funny after you clear codes. :nonono:

Idle is crazy high for a while, among other things...

[Tommy Gun]

Man this thing acts funny after you clear codes. :nonono:

Idle is crazy high for a while, among other things...

[Joe G]

Man this thing acts funny after you clear codes. :nonono:

Idle is crazy high for a while, among other things...


Man this thing acts funny after you clear codes. :nonono:

Idle is crazy high for a while, among other things...So it causes you to double post too? :wow2: :wow2:

[Tommy Gun]

Cool, a freebie post! :yay:

[68fastback]

Did you clear them by disconnecting the battery? ...it will have to lean it's 'idle' and various sensor 'masks' again.

[Tommy Gun]

Yes, disconnected the battery.

Guess you weren't in that text. :giggle:

.

[68fastback]

No prob ..I don't do texts :shades:

[Joe G]

Guess you weren't in that text. :giggle:

.I thought you didn't want people texting you now?

Make up your mind. :groan:

[Shlbylvr]

I thought you didn't want people texting you now?

Make up your mind. :groan:

:goodpost:

[Tommy Gun]

I thought you didn't want people texting you now?

Make up your mind. :groan:

I didn't exactly say that, read back.

[Joe G]

I didn't exactly say that, read back.So you just don't want US texting you?

[Tommy Gun]

:nonono:

[Joe G]

:nonono:Well then tell me what you want. :rant:




:rofl3:

[Tommy Gun]

Well then tell me what you want. :rant:




:rofl3:

I want you to clean up this tech thread. :sherriff:

[Joe G]

:mop:

[Tommy Gun]

:waiting2:

[Joe G]

:jk:

I'm not a Mod for this area. :frolic:

[Gr8snkbite]

me either..















:sofa:

[Tommy Gun]

:groan:

[Joe G]

:groan::party:

[onecrazydog]

:horsepoop:

[Tommy Gun]

My threads never get to stay technical. :conspiracy:

[68fastback]

...just fill the tank :shades:

:giggle:

[onecrazydog]

My threads never get to stay technical. :conspiracy:


It's called Karma...

[Tommy Gun]

:spitcopy:






:hey2: