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Fuel pressure sensor, fuel rail

Fuel pressure sensor, fuel rail



The sensor is supplied with power via a 200 kΩ resistor from control module pin 98 and is grounded in control module pin 87. There are two metal coated ceramic discs mounted close to each other in the pressure sensor. The disc closest to the pressure connection is thinner and bends when exerted to pressure. This changes the capacity between the metal coatings on the discs in relation to the pressure. Integrated in the sensor is a circuit that converts the capacity to an analogue voltage. The sensor measures the fuel pressure in the fuel rail. This information is evaluated by ECM, which takes action via the two fuel pressure valves.

Diagnostics

If the control module registers a malfunction in the fuel pressure valves, DTC P0191 will be generated.

If the pressure sensor input is shorted to ground, DTC P0192 will be generated.

If the pressure sensor input is shorted to B+, DTC P0193 will be generated.


System reaction to a fault

• The control module will continue to use a substitute value for the fuel pressure that is the same as the calculated.

• The idling speed will be set to 1000 rpm.

• The following limitations apply: Pedal position sensor adjustable to max 20%, fuel quantity max 20 mm 3 /combustion, fuel rail pressure max 40 MPa.