2006 Chevy Trailblazer fuel gauge stays on empty

You could use two resistors, Two different ohms specs for full and empty. Place resistor between proper wire colors in diagram. Turn on the key, If gage reacts properly to full and empty resistors, then I think the problem is the sending unit in gas tank. If not, the problem could be almost anywhere, wiring circuit--pcm--instrument cluster. I did see trouble codes relating to fuel gage sending unit. I hesitate to get into that? good luck

just replace my fuel pump /sending unit on my 06 Malibu, didn't matter if the pump was in or out of the tank, the gauge still reads wrong

take the sender unit out and check the float ,sounds like its full of petrol and not floating giving a reading of empty

{: ) A faulty fuel level sensor is most likely. But you must rule out first if theres' any problem with the gauge itself, like a stuck needle. A scan tool can command the cluster gauge to move at full sweep, effectively ruling out problem with the gauge. Without scan tool you can only approximate your judgement, like when you turn on your igniton, did the pointer move from fully down up to the Empty scale? Or did the needle never ever moved even a little?

Common problem on the 03-06 Trailblazer instrument clusters for the fuel gauge to go out. It's usually caused by one of two main problems, either the stepper motor on the cluster's circuit board is going out or the sending unit on the fuel pump is going out. Check out this blog post about the problem - Trailblazer fuel gauge problems

the fuel level gauge just went out na dthats why the light is on. to replace it you have to replace the entire sending unit. cost is $500.00 plus to have replaced. if you can live with it and keep check on your milage, I would wait for the pump to go out.

there is a fuel senor inside of the tank and it could very well be the problem

Usually if the gas gage does not work yes it is true it may be the sensor if it is electronicly controlled. the sncor will more than likley be in the tank. here is how to remove your gas tank.

1. Before servicing the vehicle, refer to the precautions section.
   
2. Relieve fuel system pressure.
   
3. Drain the fuel tank.
   
4. Remove or disconnect the following:
   
   • Negative battery cable
     
   • Fuel filler and vent hoses
     
   • Fuel tank skid plate
     
   • Fuel tank wiring connectors
     
   • Fuel supply and return lines
     
   • Fuel tank
     
   • Fuel pump assembly
     Fuel pump assembly mounting
     

To install:

1. Install or connect the following:
   
   • Fuel pump assembly
     
   • Fuel tank. Tighten the bolts to 27 ft. lbs. (36 Nm).
     
   • Fuel supply and return lines
     
   • Fuel tank wiring connectors
     
   • Fuel tank skid plate
     
   • Fuel filler and vent hoses
     
   • Negative battery cable
     
2. Start the engine and check for leaks.
   

change fuel gauge sensor in the fuel tank

khooper, in another forum, told me that "Chevron Techron Fuel System Treatment Plus can remove harmful sulfur deposits from the sending unit and a filmer agent that can prevent the deposition of said sulfur"

My 05 Trailblazer LT 2WD.
Erratic readings, and when the fuel level was below 1/2 full, the needle would sit on "Empty" with the amber light staying on.

So I went to a dealer, they replaced the fuel level sensor (p/n 19177712 SEN KIT 3.107 $118.62) with labor $270.00 for a total of $398.86 this appears to have fixed it for now.

I also talked to another mechanic who blames ethanol for these deposits !