A strange thing happened when I replaced the battery in my truck. Simple task but the result has me baffled. After hooking up the new battery, the fuel gauge reads empty and the low fuel light stays on. The fuel tank is full. I've tried my best to research this and what I'm finding is the most likely culprit is the fuel level sensor has gone bad. So I'm thinking, what are the chances that it would go bad at the same time I changed the battery? I've read other possibilities that the gauge would "fix itself" after driving it a bit and to unhook the battery for a period of time and then reconnect it. I've done the unhook and reconnect thing but have only driven it maybe 15 miles since the battery swap. Just curious if anyone else has run into this with a similar vehicle and if anyone has any thoughts. Edit: Forgot to mention that I hooked up the code reader and no codes were found.
A decent scan tool should be able to pull the fuel level up in the data stream. The sender isn't directly hooked to the gauge. If the scan tool pulls the proper fuel level then you know the sender is working. I believe cluster failures are some what common on those trucks.
Try unplugging the sending unit. Level should read over full. If that works it is probably the sending unit. There were some issues with the stepper motors in the cluster.
Dave, the sending unit is located on top of the fuel tank under the bed. Is there another location you know of to unplug the harness?
It might have just been a coincidence. But like stated above the clusters, fuel level sensors were faulty for those years. I had both go out on my 04 duramax. When you turn your key forward does the fuel gage also sweep like the others or does it stick or not move at all? Sometimes when we replaced the fuel pump the fuel level sensor wouldn't read correctly. So we had to reflash the ecm or do a simple fuel level sensor reset if I remember right.
When I turn the key to "on" the fuel gauge just stays on empty, no sweeping. How do you reflash the ECM or do a fuel level sensor reset?
Take it in to a dealership. Reflashing is a dealership only thing. If you can get a hold of a quality scan tool they can usually sweep the cluster. That will show you if indeed a stepper went out or if you have other issues. They usually also have the ability to reset the fuel level sensor. On the reflash I might be wrong about the ecm it might have been the cluster that we reflashed, ive been gone for over 7 years. I know we did reflash the cluster when we replaced it because it's not plug and play like most people think it is.
Pump, sending unit and fuel level sensor are possible culprits but replacing these truck parts can be quite daunting so I would get a wiring diagram first. It could be a bad ground or just a bad wiring connection somewhere.
Thanks for all the replies. It was the fuel level sensor so ended up changing the pump/sensor while it was apart.
