Fuel gauge went to empty on full tank and check engine light on

[Power2336]

A buddy of mine has an 06 with a Bullet Proof Diesel EGR and Diesel Site coolant filter but otherwise stock truck and has experienced this problem. He let the fuel tank go pretty low and basically empty, refilled the truck to full and drove home. After about an hour he went outside and restarted his truck and saw his fuel gauge drop to completely empty, did not go back to full and the check engine light came on. Curious on any thoughts as to what may be a cause for this before we take it in to the shop to have the DTC read..

[jtaylor75]

mines has done that before, except it has never set a code before. I hit the tank with hammer a few times (thinking the float was stuck) and it always reads the correct level afterwards. These ford trucks are known for having fuel level indication problems.

[dannyboy950]

With the fuel sensor showing empty the PCM will see this as a problem and will set the light. You can clear it but as long as the sensor reports no fuel it will come back on.