Shift lock function - GF27.10-P-2008AHW
TRANSMISSION 722.9 (except 722.930) in MODEL 204.0 as of model year 2009/YoM 08
Function requirements, Shift-Lock, general
- Circuit 15 ON
- Brake pedal operated
- Vehicle speed > 8 km/h
Shift-Lock, 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.
Shift-Lock, function sequence
The function sequence is described in the following steps:
- Park pawl function sequence
- Ignition-lock lock function sequence
- Function sequence for selector lever position "P" lock
- Function sequence of Shift-Lock-Override (manual unlocking of selector lever position "P")
Function sequence for park pawl (except code (889) Keyless-Go)
The park pawl only permits shifting out of selector lever position "P" if the ignition is switched ON via the ignition key (transmitter key (A8/1)) and the brake pedal is operated.
In order to ensure that after parking the vehicle the selector lever is shifted into selector lever position "P", the transmitter key can only be removed from the ignition lock control unit in this position (N73). 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 (with code (889) Keyless Go)
The park pawl only permits shifting out of selector lever position "P" when the ignition is switched on via the KEYLESS-GO start/stop button (S2/3) and the brake pedal is pressed.
The vehicle can only be parked via the KEYLESS-GO start/stop button when the selector lever is engaged in selector lever position "P".
Ignition-lock lock function sequence
The mechanical components of the ignition lock connects the selector lever of the center shifter console with the electronic ignition lock control unit. It prevents the transmitter key from being removed when selector lever position "P" is not engaged.
The electronic ignition lock control unit locks the transmitter key mechanically when the ignition is ON and at a vehicle speed >8 km/h.
As soon as the vehicle speed of 8 km/h is exceeded, the electronic ignition lock control unit prevents the removal of the transmitter key, as the automatic engagement of the selector lever position "P" by the electronic selector lever module control unit cannot be performed (N15/5).
The transmitter key can be removed as long as the vehicle speed remains below the speed threshold. In the process the selector lever position "P" is shifted automatically by the electronic selector lever module control unit.
Selector lever position "P" lock function sequence
The selector lever remains locked in position "P" if the following conditions are not met:
- No power supply from the electronic selector lever module control unit
- No enable signal from the drive authorization system (DAS)
- Brake pedal not actuated
Function sequence of Shift-Lock-Override
View of selector lever module from rear for model 204 up to model year 2011/YoM 10
Upon receipt of a valid drive authorization code by the electronic ignition lock control unit and brake detection by the Electronic Stability Program control unit (N30/4) the electronic selector lever module control unit actuates the locking solenoid for selector lever positions R and P (Y66/2).
The locking solenoid enables the selector lever and thus makes possible a shift operation out of selector lever position "P".
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 the selector lever position "P" is released via a pin in the locking solenoid.
The selector lever can be shifted out of selector lever position "P" by operating the lever (A) and selector lever simultaneously.
| Electrical function schematic Shift lock | PE27.19-P-2059-97FAB |