How to test a fuel gauge (tank sending unit) P0463 - GM

P0463 Fuel Level Sensor Circuit Signal High/Open trouble code. In this video I will show you how to test a fuel tank sending unit (float). Typically the spring loaded fingers that ride on the resistor in the tank will break off, ruining the sending unit. The only fix is to replace the float as an assembly or try to piece a new resistor assembly into the existing sending unit. The electrical design of the fuel tank sending unit that GM uses is identical in operation and testing as a temperature sensor. The difference is in what changes the resistance of the external resistor. On a temp sensor, it is temperature, on a fuel level sensor, it is the position of the float. For this reason, I have placed this video in my Section 6 "Thermistors" playlist. Engine Performance Diagnostics chapter 6 pages 10-11 Symptoms - in-op fuel gauge - fuel gauge stuck on full or empty - fuel gauge works some of the time - trouble code P0463 Fix - replace fuel tank sending unit Tests shown - description and operation of the electrical circuit - fuel tank level signal and ground wire tests - how to perform a circuit integrity test Tools used - scan tool - digital multimeter - back-probing tools Playlist - (Chapter 6) Temperature Sensor, Thermistor Circuit Tests https://www.youtube.com/playlist?list=PLAFYVCyenqcrUx3YSF-acO7BUpeW5hXoK Related videos - How to test a coolant temperature sensor (ECT sensor test) https://youtu.be/wxaohKkQF3o - How to test an Engine Coolant or Intake Air Temperature Sensor (any car) https://youtu.be/nksLy9MS0IQ - What s on ScannerDanner Premium? ("Chapter 6: Thermistors" Preview) https://youtu.be/8Ui1679QYbs For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book. Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium https://www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial. On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere! Disclaimer: Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.