3.7L AND 5.0L - FUEL GAUGE INDICATOR DROPS FROM APPROXIMATELY 1/2 TO EMPTY
Publication Date: October 19, 2010
Some 2011 Mustang V6 and GT vehicles may exhibit a fuel gauge indicator dropping from approximately 1/2 to 1/4 full to E, and Message Center displaying 0 Miles to Empty. This concern may be intermittent. Customers may also notice that when refueling, the vehicle takes only 7 to 10 gallons of fuel (tank capacity is 15 gallons). This concern may be due to the Fuel Pump Module (FPM) not drawing fuel from the fuel pick up located in the RH side of the fuel tank, which may be caused by an internal restriction in the FPM.
Follow the Service Procedure steps to correct the condition.
System Operation Overview:
Mustang has a saddle type fuel tank in that there is a hump in the middle of the fuel tank for the driveshaft.
There is one electric pump and fuel level sensor (FL-1) on the LH (driver side) of the fuel tank, this is the FPM.
There is a fuel pick up and fuel level sensor (FL-2) on the RH (passenger side) of the fuel tank.
The system draws fuel first from the RH side of the tank. The FPM siphons fuel from RH side of the tank via the fuel pick up. Once the fuel level on the RH is too low to siphon fuel, there are check valves that close and the fuel will now be drawn from LH side of the tank via the FPM.
The fuel level senders read the fuel levels on both sides of the tank. The two values are averaged for display on the fuel gauge.
The fuel gauge system will drop the fuel gauge indicator to E if it sees a large difference in the fuel levels from RH (FL-2) to LH (FL-1) fuel level sensors. The system is expecting the RH (FL-2) side of the tank to go down before the LH (FL-1). Sending the fuel gauge indicator to E and having the message center low fuel warning turn on warns the customer that he may run out of fuel.
Replace the FPM. Refer to Workshop Manual (WSM), Section 310-01.
Fuel Pump Module
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage IMPORTANT: Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.
2011 Mustang 3.7L, 5.0L: Replace the Fuel Pump Module (Do Not Use With Any Other Labor Operations)