Where would I find the ground on the gas tank?

Do you hear the fuel pump come on?

Yeah I don't have any problemexcept the gas guage is dead.

The fuel ank iteslf is the ground for the sending unit which I believe could be faulty.

What did you do to have it working?

In the beginning the fuel gauge would jump from a 3/4 full tank down to 1/4 tank back to 1/2 tank and so forth.

All I did was take the molex connector apart and clean it. I checked the connection to make sure it was solid and not loose. I also held it to ground and watched the fuel gage respond. After I re-connected it and gauge worked ok. I drove about 2 miles and it died again.


Potential causes of a P0463 code include:

-The signal circuit to the fuel sender is open or shorted to B+ (Battery voltage)
-The ground circuit is open, or ground path may have high resistance due to rust or missing ground strap on fuel tank
-There's an open in the fuel lever sensor's resistor to ground

I haven't had a chance to look at it yet, but probably will this week and wanted to know where to look for the tank ground as it seems the easiest thing to check first.

Thanks

You would need to test the sending unit. It could have intermittent contact causing the problem.

OK, a little more info for this one. My wife says it only does it (fluctuates) when the tank is under 3/4 full. I took some readings on the connector today. It you are looking at the connector coming from the ECM and going to the fuel tank/sending unit, with the clip on top, I numbered the pins from left to right.

Top 3 are: 1) Blk/Red 0 VDC 2) Red 12VDC 3) Blue 3.9VDC
Bottom 3: 4) bvlk -.5 VDC 5) Blk/Yell -.5VDC 6) Blue 4.2VDC

I could not get a ground reading from any pin to the tank.

Ity looks like I also have a fuel temp sensor in there.

Thanks

If the fluctuation only occurs within a certain range, the sending unit is bad.