Key-P function - GF27.10-P-3028AHX

TRANSMISSION 722.930 up to 5/31/11, 722.931 as of 6/1/11 in MODEL 212.0/2 

Key-P function requirements, general 

• Vehicle speed > 8 km/h

Key-P, general 

The designation Key-P comprises all the functions which in addition to the parking brake serve to secure the vehicle to prevent it from rolling away unintentionally.

If the ignition key is turned to position "0" (circuit 15 C) and removed while the vehicle is driving or rolling, the transmission is automatically shifted to gear range "N". As a result, the vehicle can roll "freely".

Key-P function sequence 

The function sequence is described in the following steps:

• Park pawl function sequence 
• Function sequence for selector lever position "P" lock 
• Emergency-P function sequence (see document, Emergency-P Function) 

Function sequence for park pawl in vehicles up to facelift 13 

The park pawl only permits a shift to be made from selector lever position "P" by the DIRECT SELECT INTERFACE (N150) when the transmitter key (A8/1) in the electronic ignition lock control unit (N73) is turned to "Circuit 15 ON" and the brake pedal is operated.

The "Circuit 15 ON" signal is sent from the electronic ignition lock control unit over the chassis CAN (CAN E) to the ME-SFI [ME] control unit (N3/10). The ME-SFI [ME] control unit forwards the status over the drive train CAN (CAN C) to the fully integrated transmission control unit (Y3/8n4) and the intelligent servo module for DIRECT SELECT (A80). In order to ensure that after parking the vehicle, the selector lever position "P" is active, the transmitter key can only be removed from the electronic ignition lock control unit in this position.

The vehicle is secured mechanically by blocking the park pawl gear in the transmission.

For vehicles as of facelift 13 

For vehicles as of facelift 13 the current chassis CAN will be replaced by the chassis CAN 1 (CAN E1). A second chassis CAN 2 (CAN E2) is networked between the instrument cluster (A1) and the front SAM control unit with fuse and relay module (N10/1).

With code (889) Keyless-Go

On vehicles with code (889) Keyless-Go, the selector lever position "P" is activated when the driver door is opened after the vehicle is parked.

Locking of selector lever position "P" 

Selector lever position "P" remains active if the following conditions are fulfilled:

• No power supplied to intelligent servo module for DIRECT SELECT
• No enable signal from drive authorization system stage 3 (DAS 3)
• Brake pedal not actuated