900, When gas low, A/C blows hot??????

abnjeffy · March 28, 2012

I have noticed several times now, that when my gas is so low that the light/bell indicators go off, the truck starts to do wolnky stuff. For instance, if I turn truck off and then turn it back on (with the gas still very low) the a/c will ONLY blow hot air no matter what (doesnt matter what the temp control says, still blows hot) until I fill it with gas. anyone else experienced this?

Is GM trying to FORCE me to fill it with fuel by making it unbearable to stay inside the thing?

That's messed up man, I bought the thing, if I want to run it out of gas then I should be allowed to!

Dozbubba · March 29, 2012

Lol never heard of this. Maybe someone else here has.

gmtech4 · March 29, 2012

sounds like good programming to me ,maybe it defaults the a/c off to save fuel,,who knows

as for running it that low ,,,,,,its your engine ,do what ya want lol

Wires · March 29, 2012

It's probably killiing "unnessary" peripherals to reduce engine load to get you more distance.

FYI, running with the low fuel bells on typically will bake the fuel pump over time, so really isn't recommended (it will overheat and sieze).

SouthCo · March 30, 2012

Yeah Ive never heard of this happening. I usually just refill when Ive got about a 1/4 tank, but you are entitled to run it dry if you like. Like others have said, maybe its programmed like that to get you a little extra distance, IDK.

jro909 · March 31, 2012

it would not suprise me if they put a protocol in their to kill the a/c when the fuel is low....and like stated above, your killing your fuel pump and pushing sludge through your injectors running it low constantly

BlackZ71Silverado · March 31, 2012

I was told by the dealer when I got my truck that it wil lact this way if the fuel level is very low. It is to maximize your gas mileage when it's that low. Less possibility of being stranded on the road because you are burning more fuel with the a/c on.

Not sure how true it is, never let my truck get below 1/4 tank. Not good practice allowing any vehicle to run that low on fuel often. The fuel actually acts as a coolant for the fuel pump. With a fuel level that low, your pump will heat up and will not last as long as it should.

tanked_darren · April 1, 2012

Haha I kinda want to test this now. But I hate going below 1/8 tank.

Guess you like changing fuel pumps?

abnjeffy · April 2, 2012

wow, I guess everyone felt like being a butthole over the weekend. i rarely push it that low, its just sometimes I'm tired on the way home at night and don't feel like stopping so I decide to fill it up in the morning, when I start it up it does this, it's not like I'm pulling a Kramer and trying to run it out of fuel here guys.

In all seriousness, your explanations make sense and I will try to keep at least an eight of a tank in it at all times so as to avoid any scrutiny from the community

It's just wierd that it gives you no warning, freaked me out when my a/c readout says one thing and the truck is doing another

Duronimal · April 2, 2012

I'd never heard of shutting off AC function to save gas, but it makes sense. My 'other' truck would shut off the AC function under full throttle conditions to give the most power.

I always heard that the fuel pump stays cooler with more gas in the tank. I've not searched out any official GM stance on overheating fuel pumps, but with the cost/labor to swap pumps, why push it.