Fuel pressure sensor
The fuel-pressure sensor is threaded into the fuel-supply line.
The fuel-pressure sensor monitors the pressure of the fuel in the fuel-supply line. The electric fuel pump's delivery rate is controlled by demand.
The fuel-pressure sensor is employed for the EKPS unit's electronic control of the fuel pump. The DME digital engine electronics system assesses the analogue output signal.
Strain gauges are employed to monitor the fuel pressure. A membrane equipped with strain-gauge strips is deflected by the applied pressure. The changes in resistance in the strain gauge are electronically detected by a Wheatstone bridge and evaluated. The voltage measurement then proceeds to the EKPS electronic fuel-pump control system as the actual value.
| Index | Explanation |
|---|---|
| 1 | Check valve for the brake servo booster |
| 2 | Check valve for ancillary equipment |
| 3 | Connection, high-pressure line to fuel rail |
| 4 | Fuel-pressure sensor in the fuel-supply line |
| 5 | Fuel delivery line |
| 6 | Volume control valve |
| 7 | High-pressure pump |
| 8 | Vacuum pump |
The information indicating the fuel pressure proceeds to the DME digital engine electronics system module through a signal wire. The fuel pressure signal for evaluation fluctuates depending on the pressure. The measuring range of approx. 0.5 - 4.5 volts corresponds to a fuel pressure of 0.1 MPa (1 bar) to 1.1 MPa (11 bar).
| Index | Explanation |
|---|---|
| 1 | Voltage |
| 2 | Fuel pressure characteristic curve |
| 3 | Temperature |