Fuel Gauge Inaccurate/ DTC P0461 and or P2636/ Transfer Pump Will Not Shut Off - keywords dual tank IPC empty PCM

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Owners may comment on concerns with the fuel gauge being inoperative or inaccurate, the SES mil on, or the front fuel tank is over filled with fuel, to the top of the filler cap. DTCs P0461 and/or P2636 may be found stored in the ECM. When monitoring the front fuel level sensor voltage, with the Tech 2, it may be noticed that the front tank voltage is stuck at approximately 2.2-2.3 volts. This may be caused by the front sender float stuck under the fuel filler pipe (filler spud) inside the fuel tank. The sender float arm has enough side to side movement that when the fuel level is slightly below the filler spud opening it may come in contact with the filler spud and get stuck.

Engineering has shortened the filler spud by approximately 2 1/4 inches. Since the fuel spud is sonic welded into the plastic fuel tank the correction would be to replace the tank assembly with part number 15825665. If the float arm had previously been adjusted (bent) it should also be replaced.

Note: To make sure the updated fuel tank is received, measure the length of the fuel filler spud. With the fuel filler hose removed from the fuel tank measure the length of the filler spud from the longest point inside the fuel tank to the top where the filler hose is installed. The filler spud is cut on an angel inside the tank so make sure the measurement is taken from the tip of the angle. The old design had a filler spud of approximately 11 1/4 inches, and the new design is approximately 9 inches.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.