Lower Fuel Pressure, Checking with High Pressure Pump

Lower Fuel Pressure, Checking with High Pressure Pump

• Fuel pump (FP) control module OK

• Fuel Pump (FP) OK

• Fuel filter OK

• Battery voltage at least 11 Volts

- Switch on ignition.

- Connect Vehicle Diagnosis and Service System (VAS 5052) and select the engine control module.

- Select "engine electronics" in OBD.

- Then select "Measured values" read out.

- Select measured value block 103.

- During ignition, the fuel low pressure is displayed in field 1.

• By switching the ignition off and on the Fuel Pump (FP) Control Module (J538) activates the fuel pump for several seconds.

- Measure fuel pressure.

• Specified value: Approximately 6 bar (5 to 7 bar) positive pressure

- If specified value is not attained, check the delivery rate of the electrical fuel pump.

- Check fuel pressure and residual pressure with Fuel Inj. Pressure Gauge-CIS (V.A.G 1318). Refer to => [ Fuel Pressure and Residual Pressure before High Pressure Pump, Checking ] Fuel Pressure and Residual Pressure before High Pressure Pump, Checking.