Fuel Level Sensor Voltage (P0463 code)
Fuel Level Sensor Voltage (P0463 code) My truck is a swap vehicle but the OS is a 2006 Trailblazer SS. The P0463 (fuel level sensor circut high voltage) code is being thrown and my fuel gauge reads empty all the time. So I checked the voltage at the engine harness connector where it connects to the body harness and got a reading of 5.29 volts....Is this too high? I thought all the sensors were a 5v reference....Thanks for any input...
Oh and on the body harness side I switched the multimeter to ohms and got a reading of 160 ohms which is about right for how much fuel is in the tank...
Oh and on the body harness side I switched the multimeter to ohms and got a reading of 160 ohms which is about right for how much fuel is in the tank...
5.29v is too high. Do you have a service manual? I included some info below. Even though you don't have a TB SS, this exact issue is fairly common for this vehicle, but it's usually related to the fuel level sensor or a loose connection. Here is a link from tbssowners.com with additional info that may help.
http://www.tbssowners.com/forums/sho...t=P0463&page=2
Conditions for Setting the DTC
Test the low reference circuit of the fuel level sender for an open, a high resistance, or a short to voltage between C101 and the fuel level sender.
Inspect for poor connections at the harness connector of the fuel level sender.
Inspect for poor connections at the harness connector of the PCM.
http://www.tbssowners.com/forums/sho...t=P0463&page=2
Conditions for Setting the DTC
- The fuel level signal is greater than 5 volts.
- The above condition is present for greater than 20 seconds.
- The fuel gage defaults to empty.
- The low fuel indicator illuminates.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM displays the failure information in the Failure Records on the scan tool.
- An open
- A high resistance
- Short to voltage
- An open
- A high resistance
- Short to voltage
Test the low reference circuit of the fuel level sender for an open, a high resistance, or a short to voltage between C101 and the fuel level sender.
Inspect for poor connections at the harness connector of the fuel level sender.
Inspect for poor connections at the harness connector of the PCM.
My gas gauges hasn't functioned since the teardown/rebuild of the truck. After lots of testing I finally found a terminal that was crimped too tight which cut the wire off from the crimped portion. It was not obvious at all. The insulation was stil holding on which made it look like a perfectly good connection. But one day I was retesting the wiring and out comes wire from the connector but no terminal!!! Anyways contact CPW and he sent me some terminals and I crimped it one (which took awhile because of the location and tight space above the trans where it was located on the harness). Went and put 10gal in it and turned the key....Still no reading...Well damn..But about a mile of driving it it went all the way to full but slowly starting creeping it's way back down to "E" ..It's sitting about 2 tic marks above "E" right now but Jared @ CPW said he's heard of them reading backwards with my E40 ECU. Waiting on a update for a fix right now...
Something else to consider It could be a faulty fuel level sensor (sulphur build up from gas) which causes that code and erratic fuel gauge readings. It's common on the TB SS and other newer GM trucks and SUV's. Search www.tbssowners.com and you will see a few threads on the subject.
Yeah but it's a new fuel level sender...Jared @ CPW should have a idea about how to fix it since he said he's heard of the gas gauge reading backwards on swap vehicles w/ E40 ECMs...
The gauge still reads backwards but functions perfectly otherwise. Any thoughts on how to fix the issue? I've switched both sender signal wires back and forth thinking that could be the issue but still the same thing. Maybe something in the ECM reads the ohms differently. Is there a table for this in HPtuners?
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