Recommended Procedure:

• Connect the scan tool.
• Key ON, engine OFF.
• Access and monitor the ICP and IPR PIDS while cranking the engine.

If the ICP does not meet the minimum specification of 3.5 MPa (500 psi), the injectors are not enabled by the PCM because of insufficient rail pressure.

If the IPR duty cycle is greater than 14%, ICP pressure should increase above 3.5 MPa (500 psi) provided that the IPR valve is not stuck open, the high pressure pump is building pressure and there is not an injection control pressure system leak between the high pressure pump and the injectors.

Not all high injection control pressure system issues result in a no start condition. Intermittent hard start or slow start conditions may be the result of a small leak in the injection control pressure system.

If the oil is leaking from the ICP system or if air is trapped in the ICP system, the IPR valve may be commanded fully closed while the starter is engaged in an attempt to exceed 3.5 MPa (500 psi). Monitoring RPM, IPR duty cycle, and ICP while cranking the engine, after 5 minute soak, may assist in ICP system diagnosis. ICP system leaks results in no start, hard start, slow start or intermittent hard start conditions. The symptoms caused by small leaks are present only with excessive ICP after engine start. Refer to the Expected Start Response Engine Speed, IPR Duty Cycle And ICP - Normal Operation and Entrapped Air Pocket Expected Start Response Engine Speed, IPR Duty Cycle And ICP - System Leak Or Incorrect Repair figures.

Fig 1: Expected Start Response Engine Speed, IPR Duty Cycle And ICP - Normal Operation

Courtesy of FORD MOTOR CO.

Fig 2: Entrapped Air Pocket Expected Start Response Engine Speed, IPR Duty Cycle And ICP - System Leak Or Incorrect Repair

Courtesy of FORD MOTOR CO.