PO463 code

[Tys]

Hi all,

New to site. Just bought an 04 Aveo LS four door sedan. Picked up car with near empty tank ( No check engine light. Filled with gas, drove about 100 miles and check engine light comes on. Went to Auto Zone they put a scanner on it and up pops P0423 code ( Fuel Level Sensor A Circuit High Output ). Drove car about 125 miles total. Once fuel got to 1/2 tank on fuel guage check engine light went away. Does this sound like a bad fuel sending unit ? If so can you get to the sending unit under the back seat or do you need to drop the tank ?

Thanks in advance for any advice

[Daox]

Did it come back on later? If not I wouldn't even worry about it.

[Tys]

Yes filled tank again and CEL came back on.

[ontarian_frog]

I means the ecu is getting too high a voltage from the sending unit. You'll probably need to replace it (sending unit).

[petrified.rabbit]

I would probably attempt replacing it in that case. It should be accessible through the floor under the seat?

[Tys]

Can anyone verify that I can access the sending unit from under the rear seat?

[Tys]

Replaced sending unit. Was able to get to fuel pump by pulling the bottom of the rear seat. 400 miles and exact same problem. Anybody have any other ideas?

[avguy]

The title of the thread says P0463, but the write-up says P0423. If it's the later, we're talking about a whole different animal. But if it is a P0463, you should take a careful look at the connector, and following the wiring for that sensor as far as you can go. If nothing turns up from that, you could try a new gas cap. Not saying it will solve the problem, but it's a fairly inexpensive and easy thing to try.

[Tys]

It is P0463. I will try your ideas.

Thanks

[Tys]

Happy to report back after a few tanks full of gas problem cleared itself ( I did nothing else). Fuel gauge works great. No check engine light. Fingers crossed.