Bleeding The Fuel System Following Repairs And/Or After Replacing Parts In The High-Pressure Area

Information

To avoid letting the fuel high-pressure pump run dry (danger of irreparable damage!) and to start the engine quickly after replacing parts, the following points must always be observed:

If parts/components of the fuel system between the fuel tank and fuel high-pressure pump are removed or replaced, the fuel system must be bled using PIWIS Tester II 9818 ("Bleed fuel system").
If a fuel pump, fuel line or fuel filter is removed or replaced, the fuel system must be bled once before starting the engine for the first time using PIWIS Tester II 9818 ("Bleed fuel system").
If the fuel high-pressure pump is removed or replaced , PIWIS Tester II 9818 ("Bleed fuel system") must be used to bleed the fuel system three times before starting the engine for the first time.

Prerequisite:

The vehicle must be filled with fuel.

PIWIS Tester II 9818 must be connected to the vehicle and switched on.
Switch on ignition using the original vehicle key.
Call up the "Diagnostics" menu and select the required vehicle type.
Select ==> "DME" control unit in the "Control units" menu and confirm by pressing [>>].
Select ==> "Maintenance/repairs" in the "DME control unit" menu and confirm by pressing [>>].
Select ==> "Bleed fuel system" in the "Function" menu and confirm by pressing [>>].
The fuel pumps now start up. In the engine compartment, you can see how the fuel is delivered through the fuel supply line to the high-pressure pump.
Press [F8] to start the "Bleed fuel system" function and follow the instructions on PIWIS Tester II.
Then start the engine.
After filling the fuel system, allow the engine to run at average revs for a few minutes and then switch it off again.
Check the fuel system for leaks.
Read out the fault memory using PIWIS Tester II.
Information

If there is still air in the fuel system, the engine can switch to emergency operation during the test drive. Switch off the engine and erase the fault memory. Then continue to test drive the vehicle.
Then test-drive the vehicle for > 20 km (12 miles) with at least one full-throttle acceleration.
Check the fuel system for leaks.
Check the fault memory and disconnect PIWIS Tester II.