Emergency-P function - GF27.10-P-3029AHS

TRANSMISSION 722.9 in MODEL 216.3 as of model year 2009 

/ YoM 08 

TRANSMISSION 722.9 in MODEL 216.3 (except 216.374) as of Model Year 2011 

/YoM 10 model refinement package 

TRANSMISSION 722.9 in MODEL 221.0 as of model year 2009 

/ YoM 08 

TRANSMISSION 722.9 in MODEL 221.0 (except 221.095) 

TRANSMISSION 722.9 in MODEL 221.0 (except 221.074) as of Model Year 2011 

/YoM 10 

TRANSMISSION 722.9 in MODEL 221.1 as of model year 2009 

/ YoM 08 

TRANSMISSION 722.9 in MODEL 221.1 (except 221.195) 

TRANSMISSION 722.9 in MODEL 221.1 (except 221.174) as of Model Year 2011 

/YoM 10 

Function requirements for Emergency-P, general 

• Emergency motor supply voltage

Emergency-P, general 

In emergencies, if e.g. undervoltage prevails in the on-board electrical system or the communication with the intelligent servo module for DIRECT SELECT (A80) is faulty, the emergency motor in the intelligent servo module for DIRECT SELECT is supplied with power from the onboard electrical system battery via the EIS [EZS] control unit (N73) (G1) and thus triggers the emergency-P function.

As of 1.9.08, the gearwheel drive is replaced by a belt drive for the eccentric shaft driven by the emergency motor.

Emergency-P function sequence 

The function sequence is subdivided into the following steps:

• Function sequence for start position 
• Function sequence for intermediate position 
• Function sequence for end position 
• Function sequence for cancellation 

Start position function sequence 

Start position, shown up to 31.8.08 

The emergency motor is supplied with power by the on-board electrical system battery via the EIS [EZS} control unit in an emergency, e.g. with undervoltage in the on-board electrical system, and turns the eccentric shaft.

Intermediate position function sequence 

Intermediate position, shown up to 31.8.08 

The rotating eccentric shaft presses down onto the release pin of the left slider half. This in turn causes the mechanical connection between the left and right slider halves to be broken.

End position function sequence 

End position, shown up to 31.8.08 

The pre-compressed coil spring pushes the two slider halves apart. The right slider half slides along the worm shaft to the right and pushes the range selector lever to position "P". The eccentric shaft continues to rotate until the emergency motor is no longer actuated. The actual position of the eccentric shaft is recorded by the eccentric shaft position sensor.

Function sequence for cancellation 

If undervoltage is no longer present in the on-board electrical system, the Emergency-P function is deactivated and the intelligent servo module for DIRECT SELECT reverts to its normal operating condition.

The main motor drives the worm shaft by way of the drive gears. The left slider half runs on to the right slider half, the coil spring is pre-compressed again and the mechanical connection made again.

The Emergency-P function cannot be overridden manually.

Overview of system components for automatic transmission (AT)

GF27.10-P-9992AHS