P2066 Code: Meaning, Causes, and Symptoms | OBD2 Codes

P2066 – Fuel Level Sensor ‘B’ Performance


P2066 Possible Symptoms


Engine Light ON (or Service Engine Soon Warning Light)


P2066 Possible Causes


Faulty Fuel Level Sensor,Fuel Level Sensor harness is open or shorted,Fuel Level Sensor circuit poor electrical connection


P2066 Description


In normal operation the level data from the two sending units are averaged. As stated the fuel level equalizes when the tank is relatively full. After the level drops to a point where the equalization of fuel is not likely, the right side fuel level drops to empty as auxiliary pump continues the transfer of fuel to the left side. At this point the logic looks at the level of both sending units. If the right side indicates empty and the left indicates a nominal amount, the right side is basically ignored. If everything is correct, when the gauge is below 1/3 of a tank, this should be what is actually in the left or primary side of the tank. If you were to round a corner quickly and send some of the fuel across to the right side, the right fuel level sender would rise and the left would drop. The CCN would indicate an unchanged condition, because the right side is no longer empty, and the CCN will average the two. Note: If you have access to a high line vehicle with Dot matrix EVIC and steering wheel controls, you can look at this data while driving. Use Caution to Keep Your Eyes on the Road. By pressing and holding the Music and Compass buttons simultaneously for 8 to 10 seconds you can access the raw fuel gauge data. Use the Up/Down Arrows to scroll through the data. Diagnosis If a condition occurred, where the right sending unit did not drop, but the left one did, the CCN would average the two. This could be caused by a problem with either the transfer of fuel or a malfunction of the sending unit. When these conditions occur there is a possibility that a vehicle could run out of fuel even though the gauge indicates a sufficient fuel supply. Because the right level sender is not at empty the CCN is averaging and displaying the average. Since fuel is picked up and sent from the left pump, the pump could run dry with fuel still showing on the gauge. Any diagnosis of a vehicle running out of fuel with sufficient fuel indicated on the gauge, should include verification of which sending unit is providing the level information. If fuel is indicated on the right side but not the left, either the sending unit is providing erroneous data or the transfer (scavenger) pump is not working. If the right side of the tank does contain fuel, and the left does not, it’s likely the scavenger pump is not working. This can be caused by: * nozzle plugged with debris *Disconnected, pinched or blocked in-tank lines. Additional Manual Diagnostic aidsIf this LX has steering wheel switches (and therefore a reconfigurable display in the CCN), then you can enter “Engineering Mode” by holding down both the compass/tempreature and music note buttons simultaneously until the display between the tach and speedometer switches to the Engineering mode. This takes about 5-6 seconds with the ignition in the run position. Once in “Engineering Mode” you can use the up and down arrows to arrive at a screen that shows both left and right fuel tank sending unit actual readings.