Fuel System Bleeding
Follow the points below to avoid running the high pressure fuel pump dry (very low tolerances) and to start the engine quickly after replacing the components:
- If fuel system components between the fuel tank and high pressure fuel pump are removed or replaced, then a fuel first filling must be performed.
- It is necessary to bleed the fuel system before starting the engine for the first time if the fuel pump, the fuel line (between the fuel tank and the high pressure fuel pump) or the fuel filter were removed.
- If the high pressure fuel pump was removed or replaced, then bleed the fuel system before starting the engine for the first time.
To Fill the Fuel System with Fuel, Proceed as Follows:
Procedure for Vehicles through MY 2010
-- Connect a Vehicle Diagnostic Tester.
-- Turn the ignition on.
-- Select "engine electronics" in OBD.
-- Then select "basic setting".
-- Select channel 35 from "in display field 2, pump off".
-- Press the "activate" button.
-- The fuel pump now run for approximately 60 seconds "in display field 2, pump on".
-- Repeat the process one time to make sure the fuel system is adequately filled with fuel.
Procedure for Vehicles from MY 2011
-- Connect a Vehicle Diagnostic Tester.
-- Turn the ignition on.
-- Select "engine electronics" in OBD.
-- Then select "basic setting".
-- Select "checking the transfer fuel pump".
-- Press the "Start" button.
-- The fuel pumps start.
-- The fuel pumps must run for approximately 1 minute to make sure the fuel system is sufficiently filled with fuel.
Procedure for All Vehicles
-- Then start the engine.
-- After filling the fuel system, let the engine run at a moderate speed for a few minutes and then stop it.
-- Check fuel system for leaks.
-- Erase the DTC memory with a scan tool.
-- Perform a road test where the accelerator pedal is pressed all the way down at least one time. Then check the high pressure area again for leaks.
-- Check the DTC memory.