Thread: P0463 Fuel Level Sensor Circuit High Voltage = ECM, PCM code

Just picked up a 2005 GTP for the used car lot I work for and........


Getting P0463 Fuel Level Sensor Circuit High Voltage = ECM, PCM code.

The fuel gauge does its normal start up cycle, then it goes back all the way up to full, stays there for 3-5 seconds and then drops down to empty and stays there. We put in about 7 gallons of fuel and same thing!

I took the car for a drive and under half throttle it runs and performs fine...responsive and drives well. The second you floor it the car falls flat on its face...acts as if it hits a rev limiter even though the RPM's are no where near the red line...just seems the car is starving for fuel or air.



I checked the following:

Gas line PSI is at a solid 60
All plugs read the right voltage
Our scanner shows the cars fuel is at 100% right at start up, then drops down.
The voltage at the pump stays at 14V, does not change at all.


What do you guys think this is from??

Hmmm...I don't mind changing out the fuel pump or what not but I am afraid of the car falling on its face at WOT...

.............

Originally Posted by Fivefingerdeathpunch

its not really a float.

Circuit Description

The fuel level sensor changes resistance based on fuel level. The PCM monitors the signal circuit of the fuel level sensor in order to determine fuel level. When the fuel tank is full, the sensor resistance is high and the PCM senses a high signal voltage. When the fuel tank is empty, the sensor resistance is low and the PCM senses a low signal voltage. The PCM uses the signal circuit of the fuel level sensor in order to calculate the total remaining fuel percent in the tank. The PCM sends the fuel level percent via the class 2 serial data circuit to the IPC in order to control the fuel gage. The fuel level information is also used for misfire and EVAP diagnostics.

I do get misfire and EVAP pending codes...so maybe the WOT issue will be resolved with the pump change???

Please say yes LOL

Resolved!

Gas meter issue....pump in the car didn't have a sending unit, got a new pump.

Misfiring under load...new coil packs, plugs, and wires.

Im going to bump this up, got that p0463 code the other day in my grand prix (2001 se)

On the resistance thing 5finger was talking about, i can put the car in drive the gas gauge will go up to F, i put the car in neutral the gauge will drop down and up and all over the place.. The car runs great, but this thing is pissing me off. Did they make holes in the floor for easy access on the grand prixs for the fuel pump?? I know my previous 2001 bonneville did..
Do i need the whole sending unit or can i just pick up the fuel level sensor?? thanks