Vehicle: 2008 Ford F 150, 4WD, V8-5.4L Flex Fuel, Automatic Transmission/Transaxle
Problem: The fuel gauge does not read the correct fuel level. DTCs B1201 and P0463 are set. The tech checked the wiring between the sending unit and instrument cluster and found no problems. The fuel gauge sending unit was replaced – same problem.
Details: The tech then checked the LG/OG wire that comes from the central junction box to the fuel module at the fuel tank. The wire had lost voltage at connector C3138, located under the cab. This wire is only used for flex-fuel vehicles. The LG/OG wire pin was corroded and had lost connection. NOTE: If the wire doesn’t have voltage at the connector with the key on, check for voltage back at the Central Junction Box.
Confirmed Repair: The tech replaced the male and female pins in connector C3138. The fuel gauge now operates normally.