Fuel injection System

Safety Precautions

If special testing equipment is required during road test, note the following:





Improperly secured testing and measuring equipment and distraction during a road test increase the risk of an accident.

Risk of passenger airbag deploying in an accident.

• Operating testing and measuring equipment while driving creates a distraction.

• There is an increased risk of injury due to unsecured testing and measuring equipment.

• Position passenger's seat as far back as possible.

• Only use the Vehicle Diagnosis and Service System (VAS 5052) or Diagnostic System (VAS 5053).

• Testing and measuring instruments - 1 - must lay flat on the passenger's thighs and be operated by him or her, as shown in the illustration.

Fuel system is under pressure! Fuel pressure must be reduced to a residual pressure before opening high pressure area of injection system. Refer to => [ Before Opening High Pressure Fuel Injection System ] Service and Repair.

After reducing high pressure, connection should be opened immediately. To do this, place a cloth around the connection to reduce residual pressure (approximately 6 bar).

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system, always observe the following:

• The battery must be disconnected before opening the fuel system, for safety reasons. The fuel pump may be activated by the driver's door contact switch.

• Individuals with a pacemaker must not stay in the danger area of high voltage systems, e.g. ignition systems, xenon light.

• Fuel lines must not be opened when engine is running.

• Only disconnect and reconnect wires for injection and ignition system, including test leads, when ignition is switched off.

• If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect connectors from ignition coils and remove fuse for electric fuel pump.

• 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.

• If the DTC memory was erased, the readiness code must be generated.

• Cleaning the engine should only be performed with ignition switched off.

• The battery must only be disconnected and connected with the ignition switched off, since the Engine Control Module can otherwise be damaged.

• If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect the four connectors for ignition coils, using the ignition coil puller (T40039). Refer to => [ Ignition Coils with Power Output Stages ] Service and Repair. Also remove fuse from Fuel Pump (FP) Control Module (J538).





• The fuse is located in the fuse holder in the right of the luggage compartment.

• By removing fuse - SF 6 -, the voltage supply to terminal 30 for the Fuel Pump (FP) Control Module (J538) is interrupted.