P0748 Fuel press. regulator (high press. pump input)

			Test results
0	COMPONENT CONCERNED	PRELIMINARY CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Engine management control unit	Check if "Overtemperature" is shown in the error details	Go to Step 1	The error detail is "Overtemperature"	Go to Step 5
1	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Fuel pressure regulator wiring	Check for the presence of short circuit to Vbatt See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 2	Presence of short circuit to Vbatt.	Restore correct insulation to battery positive
2	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Fuel pressure regulator wiring	Check for short circuits to earth See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 3	Presence of short circuit to earth	Restore correct insulation to earth
3	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Fuel pressure regulator wiring	Check for an open circuit See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 4	Presence of open circuit	Restore the correct connections
4	COMPONENT CONCERNED	CHECK USING DIAGNOSIS EQUIPMENT	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Engine management control unit	Keep the diagnosis equipment connected to the engine management control unit and use Active Diagnosis to check whether the high pressure pump inlet pressure regulator is working correctly	End of diagnosis	Pressure regulator faulty	Replace the high pressure pump Op. 1060E10