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Fuel pressure valve, fuel rail

Fuel pressure valve, fuel rail



There are two solenoid valves in the fuel pump that regulate the pressure in the fuel rail depending on the pressure that is required. The pressure varies between 25 MPa at idling speed and about 135 MPa at full load. The valves are mounted on the rear of the fuel pump and are controlled by ECM, which sends PWM signals.

At low engine speeds and low loads, the control valves will allow a small amount of fuel to pass to the high-pressure pump, which delivers a low pressure. As the load increases, the control valves will allow more fuel to pass, which gives a higher pressure.

Diagnostics

If any of the valves for regulating fuel pressure or the corresponding wiring harness are out of order, it can be indicated by the following DTCs being generated:


P0253 Fuel pressure valves. Short to Ground/Open.

P0254 Fuel pressure valves. Short to B+.

P0258 Fuel pressure valves. Supply voltage, Short to Ground/Open.

P0259 Fuel pressure valves. Internal short.


System reaction to a fault


P0253 and P0258

The following limitations apply: Pedal position sensor adjustable to max 40%, fuel quantity max 30 mm 3 /combustion, fuel rail pressure max 60 M Pa, idling speed set to 1000 rpm.



P0254 and P0259

Engine turns off.