Fuel System Safety Precautions

Note the following when working on the fuel system:

WARNING:

There is a risk of injury because the fuel is under very high pressure.

Fuel pressure in high pressure pipe can be up to 120 bar (1740 psi)! Always follow the safety precautions when reducing the pressure in the high pressure area.
Reduce the pressure in the high pressure area. Refer to the appropriate service information .
The fuel supply line is under pressure. To prevent injuries and skin contact, wear protective goggles and protective clothing. Wrap a clean cloth around the connection before loosening hose connections. Remove the hose connection carefully to release the pressure.

Fuel coming into contact with skin poses a health risk.

Danger due to leaking fuel

For safety reasons, switch off the current to the fuel pump before opening the fuel system. Otherwise, the fuel pump will activate when the driver door is opened.
Disconnect the power supply by removing the fuse for the Fuel Pump Control Module -J538- / fuel delivery unit. Refer to the appropriate Wiring Diagram or disconnect the battery.

Danger of explosion due to cell phones.

Perform the following steps before starting work on the fuel system:

The fuel tank may only be partially full. How much fuel can remain in the fuel tank may be read in the respective work description. Drain the fuel tank, if necessary. Refer to FUEL TANK, DRAINING .
Before starting work, switch on the exhaust extraction system and place an extraction hose close to the installation opening of the fuel tank to extract escaping 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.

To prevent personal injury and damage to the injection and ignition system, observe the following:

Individuals with a pacemaker must not stay in the danger area of high voltage systems, for example ignition systems, xenon light.
Do not touch or disconnect ignition coils with power output stages when the engine is running or turning at starting RPM.
The ignition must be switched off before connecting or disconnecting injection and ignition system wiring or tester cables.
Wash the engine only when the ignition is turned off.
Note the color coding when installing the coupling.
The connector couplings must "audibly" engage when locking.
Pull on the connections when they are connected to make sure they are secured correctly.
Delete any Diagnostic Trouble Code (DTC) memory entries that occurred during testing or assembly Vehicle Diagnostic Tester, Guided Functions , Check DTC Memory , and then Generate Readiness Code .

CAUTION:

Risk of damaging electronic components when disconnecting the battery.

Observe the steps for disconnecting the battery.
Disconnect the battery only when the ignition is turned off. Refer to Battery, Disconnecting and Connecting .