BMW 7 Series: Check BMW Diagnosis System For Excess Pressure And Vacuum (N63)

IMPORTANT: Excess pressure and vacuum lines are identified by the size of the connection fittings and color-coded red and blue and must not be mixed up with each other.

Mixing up the functions will result in damage to the engine.

Necessary preliminary work

• Release upper section of intake air filter.
• Prepare BMW diagnosis system.
• Start diagnostic program.
  1. Power train
  2. Engine electronics
  3. Air supply
  4. Charging pressure control Oder Perception

Lack of power

Note on ordering:

• Workshop equipment.
• Workshop planning.
• Workshop equipment catalogue.
• Measuring and test equipment.
• No. 81 29 0 426 464

Pressure measurement

Prepare BMW diagnosis system on excess pressure diagnosis unit.

1. Screw in pressure sensor.
2. Overpressure connection (Blue).
3. Connect stimuli cables (3) to positive and negative.
4. Connect 12V battery cables (4) to vehicle battery positive and negative.

Fig. 445: Measuring Pressure

Secure seal plug (1) with union nut (2) in intake port and seal.

NOTE: Twin-Turbo: both intake ports must be sealed.

Fig. 446: Identifying Seal Plug And Union Nut

Insert Blue pneumatic hose (4) in pneumatic coupling (2) of sealing plug (1).

Seal plug (3) has no pneumatic coupling.

Fig. 447: Inserting Blue Pneumatic Hose In Pneumatic Coupling Of Sealing Plug

Vacuum pressure measurement

Prepare diagnosis tester on vacuum diagnosis unit.

1. Screw in pressure sensor.
2. Connect stimuli cables (2) to positive and negative.
3. Connect 12V battery cables (3) to vehicle battery positive and negative.
4. Controller for vacuum connection.
5. Vacuum connection (Red).

Fig. 448: Measuring Vacuum Pressure

Calibration for vacuum pressure measurement

Seal shutoff tap (2) in direction of arrow.

Release lock nut on controller (1).

Carry out pressure adjustment in accordance with BMW diagnosis instruction.

Secure controller (1) hand-tight against turning.

Open shutoff tap (2) again.

Fig. 449: Releasing Lock Nut On Controller

Connections on EPPC

1. Connection (VAC) to vacuum reservoir.
2. Connection (OUT) with ring to exhaust turbocharger.

Fig. 450: Identifying Vacuum Reservoir Connection (VAC)

Vacuum activation, cylinders 1-4

Detach red vacuum line from vacuum unit.

Prepare T-piece (5) with vacuum lines for measurement.

Connect red vacuum line (1) with vacuum unit (2) and quick-release coupling (3).

Open shutoff tap (4).

NOTE: Observe diagnosis instructions.

Fig. 451: Identifying Red Vacuum Line, Vacuum Unit And Quick-Release Coupling

Vacuum activation, cylinders 5-8

Detach blue vacuum line from vacuum unit.

Prepare T-piece (5) with vacuum lines for measurement.

Connect blue vacuum line (1) with vacuum unit (2) and quick-release coupling (3).

Open shutoff tap (4).

Fig. 452: Identifying Blue Vacuum Line, Vacuum Unit And Quick-Release Coupling

Exhaust turbocharger, cylinders 1-4

Initial position (1) of wastegate linkage depressurized.

Wastegate valve opened.

Fig. 453: Identifying Initial Position Of Wastegate Linkage Depressurized

Initial position (1) of wastegate linkage with vacuum pressure.

Wastegate valve closed.

Fig. 454: Identifying Initial Position Of Wastegate Linkage With Vacuum Pressure

Exhaust turbocharger, cylinders 5-8

Initial position (1) of wastegate linkage depressurized.

Wastegate valve opened.

Fig. 455: Identifying Initial Position Of Wastegate Linkage Depressurized

Initial position (1) of wastegate linkage with vacuum pressure.

Wastegate valve closed.

Fig. 456: Identifying Initial Position Of Wastegate Linkage With Vacuum Pressure

Check wastegate valve with vacuum

Wastegate valves must be opened without vacuum.

The wastegate valves must close if a vacuum pressure is applied at the wastegate sockets (see BMW diagnosis system).

Check shaft on turbine wheel for rotatability.

Fig. 457: Checking Wastegate Valve With Vacuum

Follow diagnosis instructions.

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