Safety Precautions, Working On Fuel Supply System

CAUTION:

For all repair work, especially in the engine compartment due to the tight working conditions, the following must be observed:

Route lines of all types for example for fuel, coolant and refrigerant, vacuum and electrical wires so that the original wiring diagram is followed.
To prevent damage to the lines, make sure there is sufficient clearance to all moving or hot components.

Always observe the following when removing and installing the Fuel Level Sensor -G- or the fuel pump from full or partially filled fuel tanks.

Remove the fuel pump fuse. For the fuse assignment. Refer to the appropriate WIRING DIAGRAM.

WARNING:

Fuel system is under pressure! Wear eye protection and safety gloves in order to avoid injuries and skin contact. Wrap a cloth around the connection before loosening hose connections. Remove the hose connection carefully to release the pressure.

Right before starting work, switch the exhaust extraction system on and place an extraction hose close to the fuel tank installation opening to extract fuel fumes. If no exhaust extraction system is available, a radial fan (as long as motor is not in air flow) with a displacement greater than 15 m³ /h can be used.
Do not let fuel come in contact with bare skin. Wear fuel-resistant gloves.

The Engine Control Module -J623- is equipped with On Board Diagnostics (OBD). Before repairs such as fault finding, check the DTC memory first. Also the vacuum hoses and connections must be checked (unmetered air).
The fuel hoses on the engine may only be secured with spring clamps according to the parts information. The use of clamp or screw type clips is not permissible.
Ignition must be switched off when disconnecting the battery. If a coded radio is equipped, the code must be requested before disconnecting the battery.
Follow all steps after connecting the battery. Refer to BATTERY . .
For proper function of the electrical components, a voltage of at least 11.5 V is required.
Do not use sealants containing silicone. Particles of silicone drawn into the engine, will not be burnt in the engine and damage the oxygen sensor.
If the engine only starts briefly and then turns off again after troubleshooting, repairs or checking the components, it may be that the immobilizer is blocking the engine control module. Control module must then be adapted if necessary.
It is possible that the control module will recognize a malfunction and store a DTC during some tests. Therefore after completing all checks and repairs, the DTC memory must be checked and if necessary erased.
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 the driver-side door is opened, the fuel pump is activated for 2 seconds so that pressure builds in the fuel system. This improves comfort of engine start-up behavior.