Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
Description and Operation 1-73
Fuel Systems
Fuel Pump Control Module Duty Cycle Signals
Duty Cycle | Comments |
|---|---|
20% | This duty cycle indicates the fuel pump control module is receiving an invalid duty cycle from the PCM. |
40% | This duty cycle indicates the fuel pump control module is receiving an invalid event notification signal from the RCM. |
60% | This duty cycle indicates the fuel pump control module is functioning normally. |
80% | This duty cycle indicates the fuel pump control module is detecting a concern with the secondary circuits. |
For additional information, refer to Powertrain Control Hardware, Fuel Pump Control Module in this section.
Mechanical Returnless Fuel System (MRFS) — EcoSport And KA
The MRFS uses a fuel tank with reservoir, the fuel pump, the fuel supply line, the fuel rail, and fuel injectors. For additional information on the fuel system components, refer to Engine Control Components in this section. Operation of the system is as follows:
1. The fuel delivery system is enabled during ignition ON, engine OFF for 1 second and during crank or running mode once the PCM receives a crankshaft position (CKP) sensor signal.
2. The fuel pump logic is defined in the fuel system control strategy and is carried out by the PCM or the body control module (BCM).
3. The PCM or BCM grounds the fuel pump relay, which provides power to the fuel pump.
4. The PCM monitors the FPPWR circuit by way of a spliced FPM circuit.
5. The fuel injector is a solenoid-operated valve that meters the fuel flow to each combustion cylinder. The fuel injector is opened and closed a constant number of times per crankshaft revolution. The amount of fuel is controlled by the length of time the fuel injector is held open. The fuel injector is normally closed and is operated by the PCM.
6. There are 3 to 5 filtering or screening devices in the fuel delivery system. For additional information, refer to Fuel Systems, in this section.
7. The FP assembly contains the fuel pump, the fuel pressure regulator, lifetime fuel filter and the fuel sender assembly. The fuel pressure regulator is attached to the FP assembly and regulates the pressure of the fuel supplied to the fuel injectors. The fuel pressure regulator controls the pressure of the clean fuel as the fuel returns from the fuel filter. The fuel pressure regulator is a diaphragm-operated relief valve. Fuel pressure is established by a spring preload applied to the diaphragm. The FP assembly is located in the fuel tank.
Typical MRFS (KA)
2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.