FixVault

Emergency-P Function - GF27.10-P-3029AHG

Transmission 722.9 in model 463 as of model year 2013 

Emergency-P, general 

If, for example, undervoltage is present in the on-board electrical system or communication with the intelligent servo module for DIRECT SELECT (A80) is faulty, the emergency motor (31) in the intelligent servo module for DIRECT SELECT is supplied with power from the electronic ignition lock control unit (N73), thereby triggering the Emergency-P function. The Emergency-P function prevents the vehicle from rolling away inadvertently.

Start position 

G13656983Courtesy of MERCEDES-BENZ USA

The emergency motor (31) is supplied with power and turns the eccentric shaft (34).

Intermediate position 

G13656984Courtesy of MERCEDES-BENZ USA

The rotating eccentric shaft (34) presses on the release pin (32/4) of the left carriage half (32/1).

This in turn breaks the mechanical connection between the left carriage half (32/1) and the right carriage half (32/2).

End position 

G13656985Courtesy of MERCEDES-BENZ USA

The pre-compressed coil spring (32/3) pushes the two carriage halves (32/1, 32/2) apart. The right carriage half (32/2) slides along the threaded rod (33) to the right and pushes the range selector lever (35) to position "P". The eccentric shaft (34) rotates until the emergency motor (31) is no longer actuated. The actual position of the eccentric shaft (34) is detected by the eccentric shaft (40) position sensor and passed on to the electronics of the intelligent servo module for DIRECT SELECT.

Cancellation 

The Emergency-P function is canceled automatically if, for example, undervoltage is no longer present in the on-board electrical system. The main motor (30) rotates the threaded rod (33) over the drive belt (42). The left carriage half (32/1) runs on to the right carriage half (32/2), the coil spring (32/3) is pre-compressed again and the mechanical connection is restored.

IMPORTANT The Emergency-P function cannot be overridden manually.

  Overview of system components for automatic transmission (AT)   GF27.10-P-9992AHG