Fuel Pump Control - ERFS
NOTE:
The Mustang 5.8L uses 2 fuel pump control modules to control fuel for the fuel delivery system. The PCM sends one FP duty cycle on the fuel pump control (FPC) circuit. Both fuel pump control modules use this circuit.
The FP signal is a duty cycle command sent from the PCM to the fuel pump control module. The fuel pump control module uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the pump OFF. When the ignition is turned ON, the electric fuel pump runs for about 1 second and is requested OFF by the PCM if engine rotation is not detected.
FUEL PUMP DUTY CYCLE OUTPUT FROM PCM (MUSTANG 5.8L)
| FP Duty Cycle Command | PCM Status | Fuel Pump Control Module Actions |
|---|---|---|
| 0-15% | Invalid OFF duty cycle. | The fuel pump control module sends a 20% duty cycle signal on the fuel pump monitor (FPM) circuit. The fuel pump is OFF. |
| 5-51% | Normal operation. | The fuel pump control module operates the fuel pump at the speed requested. FP duty cycle times 2 equals pump speed % of full ON. For example, FP duty cycle equals 42%. 42 times 2 equals 84. Pump is run at 84% of full ON. The fuel pump control module sends a 60% duty cycle signal on FPM circuit. |
| 51-67% | Invalid ON duty cycle. | The fuel pump control module sends a 20% duty cycle signal on the FPM circuit. The fuel pump is OFF. |
| 67-83% | Valid OFF duty cycle. | The fuel pump control module sends a 60% duty cycle signal on FPM circuit. The fuel pump is OFF. |
| 83-100% | Invalid ON duty cycle. | The fuel pump control module sends a 20% duty cycle signal on the FPM circuit. The fuel pump is OFF. |
For additional information, refer to FUEL PUMP CONTROL MODULE .