Ford Transit 2002 Owner's Manual page 1387

becomes inverted, the fuel tank vent valves close preventing fuel being lost from the fuel
tank.
If the fuel tank vent valves or the fuel vapor lines connected to the vent valves become
restricted, vehicle performance will become impaired. The inability of the fuel tank to
substitute the fuel demanded by the fuel charging system with air, will create a negative
pressure in the fuel tank which will result in reduced fuel flow to the fuel pump.
Fuel Level Sensor
Item Part Number
1 -
2 -
3 -
The fuel level sensor is located in the top of the fuel tank and is retained by a fuel level
sensor locking ring and seal.
The fuel level sensor consists of a mechanical float attached to a variable resistor card by
means of a rigid wire lever. The resistor card has two electrical elements. One element is
solid and one element is a variable resistor. The resistance value created by the resistor
card is sent to the central junction box (CJB) through a hard wired circuit. The CJB
distributes the information from the fuel level sensor to the instrument cluster and the
powertrain control module (PCM) using the controller area network (CAN) circuits.
The fuel level sensor resistor card can be susceptible to contaminated fuel, which can affect
electrical continuity. This condition is normally temporary and self-rectifying. If the fuel
level sensor has been removed, moving the rigid wire lever from empty to full a minimum
of 10 times will normally be as effective as installing a new fuel level sensor. The most
common symptom of contamination occurs after refuelling where the electrical contact
moves to an area of the resistor card which has not been used for several days. This results
in a very slow movement of the fuel gauge pointer from empty to full over approximately
15 minutes. In more extreme cases where the resistor card resistance is continuously
outside the permitted range for more than 33 seconds, a DTC will be set in the CJB and the
fuel gauge pointer will fall to its key-off position. In all cases where the fuel level sensor is
suspected of being inoperative, worn or damaged, the Worldwide Diagnostic System (WDS)
diagnostic procedures must be followed before any parts are dismantled.
Description
Fuel level sensor locking ring
Fuel level sensor sealing ring
Fuel level sensor
http://vnx.su