Fuel Delivery and Air Induction: Description and Operation

Fuel Injection System

• The mass airflow sensor (G70) is no longer installed from MY 09. The intake air temperature sensor (G42) is installed on the intake manifold with the manifold absolute pressure sensor (G71).

• If the fuel system was opened, the system must be bled before starting the engine. Refer to => [ Fuel System, Bleeding ] Fuel System, Bleeding.

• Fuel hoses in the engine compartment may only be secured with spring type clamps. The use of clamp or screw type clips is not permissible.

• The ignition must be turned off when disconnecting the battery. Obtain the radio code for radios with a anti-theft code before disconnecting battery.

• Observe the safety precautions after connecting the battery.

• For trouble free operation of the electrical components a voltage of at least 11.5 volts is necessary.

• Do not use sealants containing silicone. Particles of silicone drawn into the engine, will not be burnt in the engine and will damage the oxygen sensor.

• If the engine only starts briefly and then shuts off again after, troubleshooting, repairs or checking of the components, it may be that the immobilizer is blocking the Engine Control Module (ECM). The ECM may have to be adapted then. Refer to "Guided Functions" in the vehicle diagnostic tester.

• It is possible that the ECM will recognize a malfunction and store a Diagnostic Trouble Code (DTC) during some tests. After completing all tests and repairs, the DTC memory should therefore be checked and erased as necessary. Refer to => [ Engine Control Module DTC Memory, Checking and Erasing ] Engine Control Module DTC Memory, Checking and Erasing.

• Vehicles with an airbag are equipped with an emergency fuel shut off system. It reduces the risk of fire in an accident because the fuel pump relay switches the fuel pump off.

• When opening the drivers door, the fuel pump is activated for 2 seconds to build pressure in the fuel system. This improves comfort of engine startup behavior.

Follow all safety precautions. Refer to => [ Safety Precautions ] Multiport Fuel Injection.

Note the rules of cleanliness. Refer to => [ Clean Working Conditions ] Multiport Fuel Injection.

Technical data, refer to => [ Technical Data ] [1][2]Idle Speed.