GF27.10-P-2008AHC Shift-Lock, Function

GF27.10-P-2008AHC Shift-lock, function
- Transmission 722.902/904/906/908


Function requirements
^ Circuit 15 ON
^ Brake pedal operated
^ Vehicle speed greater than 8 km/h

General
The term shift lock combines the functions which, in addition to the parking brake, offer an additional safeguard for the vehicle to prevent it moving off unintentionally.

Function sequence
The function sequence is described in the following steps:
^ Function sequence of park pawl (except code (889) Keyless Go)
^ Function sequence of park pawl (with code (889) Keyless Go)
^ Function sequence of ignition lock lock (except code (889) Keyless Go)
^ Function sequence of selector lever position "P" lock
^ Function sequence of Shift-Lock-Override (manual unlocking of selector lever position "P")

The vehicle is secured mechanically by locking the transmission with the park pawl gear. Selector lever position "P" can be released manually (Shift-Lock override) in the event of mechanical or electrical faults.

Function sequence of park pawl (except code (889) Keyless Go)
The park pawl only allows you to shift out of selector lever position "P" if status "circuit 15 ON" has been enabled via the transmitter key (A8/1) and the brake pedal has been operated. In order to ensure that after parking the vehicle the selector lever is engaged in selector lever position "P", the transmitter key can only be removed from the electronic ignition lock control unit in this position (N73).

Function sequence of park pawl (with code (889) Keyless Go)
The park pawl only allows you to shift out of selector lever position "P" if status "circuit 15 ON" has been enabled via the KEYLESS-GO start/stop button (S2/3) and the brake pedal has been operated.

The vehicle can only be parked via the KEYLESS-GO start/stop button when the selector lever is engaged in selector lever position "P".

Function sequence of ignition lock lock (except code (889) Keyless Go)
The mechanical components of the ignition lock lock prevent the removal of the transmitter key when selector lever position "P" is not engaged and with "circuit 15 ON" and a vehicle speed greater than 8 km/h.

Function sequence of selector lever position "P" lock
The selector lever remains locked in position "P" if the following conditions are not met:
- No power supply from electronic selector lever module control unit (N15/5)
- No enable from drive authorization system stage 3 (DAS 3)
- Brake pedal not actuated

Upon receipt of a valid drive authorization code from the electronic ignition lock control unit and a brake detection from the Electronic Stability Program control unit (N30/4) (except code (233) DISTRONIC PLUS) or Electronic Stability Program Premium control unit (N30/7) (with code (233) DISTRONIC PLUS) the electronic selector lever module control unit actuates the selector lever position R and P (Y66/2) locking solenoid.

The selector lever positions R and P locking solenoid releases the selector lever and thus permits a shift out of selector lever position "P".

Component Identification:

Function sequence of Shift-Lock-Override (manual unlocking of selector lever position "P")

View of electronic selector lever module control unit from above
Should it not be possible to engage a gear range from selector lever position "P" for reason of mechanical or electrical faults, the lock of selector lever position "P" can be released manually. To do this, the rubber boot on the selector lever cover must be unclipped and, using a suitable tool, pressed through the guide underneath on the lever (A) (arrow).

The lock of selector position "P" is unlocked via a pin in the selector lever positions R and P locking solenoid.

The selector lever can be shifted out of selector lever position "P" when the lever (A) is actuated simultaneously.