General Maintenance & Repairs - what triggers the gas light?

does the gas gauge trigger the gas light to come on, or does the gas light come on from a reading directly from the tank? i'm wondering bc when i reinstalled my gas gauge needle after putting new gauges in, im not sure if the gas gauge is right on.

anybody know?

gm fuel sender is a wire wire system for fuel level. It sould be a resistance So the pcm or bcm should see a low value as low fuel. It doesn't answer your quesstion. But just some ideas.

I don't think I'm much help but sometimes my gauge doesn't work. IT just sits between E and 1/4. IT doesn't do it all the time but when it does the check gauges light comes on. I think it's my sender unit that's going out so I'm guessing that's what sets off the light too.

so im fine if my gas gauge is a litle off? good....thanks

uhh our gas gauges are worthless I went like 50 miles on E once only to fill up only 13 gallons when I stopped for gas. WTF!

so im fine if my gas gauge is a litle off? good....thanks
yes, your gauge is independent of your light.

If you notice on the needle, there is a little tab on the needle that stops the needle when it hits the corresponding indent (?) on the gauge cluster part. I just filled my tank up one day and put the needle back on at this 'max' position.
There is also a little nub on the overlay bezel. I haven't put everything back together, but I assume that this keeps the needle just off of the max position contact.
I am trying to hurry and type this so I may have not explained very clearly!
Just another way to put the needle on and be accurate (I hope!!).

Ive ran out of gas before, but the light NEVER came on. I was like WTF, seriously it pissed me off.

I've ran out once before too, and had it very, very close to running out again.... but no light ever came on..

There is a variable resistor in the gas tank. The computer reads the resistance and looks at a calibration table. Then it tells the IP cluster a voltage which shows up as a position between E--F on the gas gauge.

The gas gauge of a 2002 Cavalier is much more accurate then most F-bodies.

Does anyone know why it takes 15 mintues for the gas gauge to go from E to F when you fill up? I would like to know!

After i fill up my gauge switches to past F in approx. 4 sec.

Anyways, i too have noticed that light coming on sometimes when i have 4 gallons of gas left in the tank.. when should it REALLY come on though?

After i fill up my gauge switches to past F in approx. 4 sec.

Anyways, i too have noticed that light coming on sometimes when i have 4 gallons of gas left in the tank.. when should it REALLY come on though?

What year? v8?

2002 FB V6... I should be asleep xD

I have yet to run out of gas in my TA, the light has allways come on, the light says "check gauges", and the gas gauge is accuarate... and i dont know what triggers the light but it works damn good.

Damn. My gas gauge is very slow to change when filling. Most be someone wrong with my car. lol

Did the 98 cars have a light? I ran mine out once and burnt up the fuel pump. I never saw a light come on once while I had the car. My light comes on alot in the '01 b/c I usually let it get pretty low before filling up.

ok my guage works fine once you know where it runs out witch on my car it WAY past e but i know the spot (have ran it out of gas alot thow) but the light comes on at a little less than a 1/4 tank is there any way to change where it comes on???

oh yea and if the car is running the gas needle takes long time. but if you turn off key and restart it like you are soposed to do it should recheck tank and needle moves fast.

ok my guage works fine once you know where it runs out witch on my car it WAY past e but i know the spot (have ran it out of gas alot thow) but the light comes on at a little less than a 1/4 tank is there any way to change where it comes on???

YES THERE IS!!

If you have EFIlive go to the section on 'fuel system.' You can change the fuel tank size, fuel gague calibration, and how many liters it reads per the given signal by the fuel sender.

It a nice little program!

After getting my TA i ran the gas down to see when the light would come on.. No F-ing gas light.. Ended up burning up the fuel pump while trying to turn it on.. :bang: Live and learn, now i don't let it go past 1/4 tank..