Rear passenger compartment backrest release function - GF91.29-P-0014RF

Model 205.2, 253

Fig 1: Rear Passenger Compartment Backrest Release - Block Diagram

Courtesy of MERCEDES-BENZ USA

Function requirements, general

Vehicle not locked from outside or
At least one door open or
Liftgate open
Vehicle speed v < 12 km/h

The electronic ignition lock control unit sends the status of the central locking system over the interior CAN to the rear SAM control unit.

The front door control units and rear door control units send the respective door status via interior CAN to the rear SAM control unit. The status of the liftgate is detected by the rear SAM control unit itself. The instrument cluster sends the vehicle speed via user interface CAN, electronic ignition lock control unit and interior CAN to the rear SAM control unit.

Rear backrest release, general

In order to increase the loading volume of the vehicle, the split backrest in the rear can be unlocked electrically and then folded over towards the front.

Function sequence for rear backrest release

Operating the respective backrest release button unlocks the corresponding backrest in the rear compartment.

The rear SAM control unit reads in the status of the respective backrest release button directly and then actuates the corresponding rear backrest release actuator. The backrest is released and folded over towards the front by means of manual spring force.

If a backrest has been released but not folded over, a message is issued by the instrument cluster. The rear SAM control unit reads in the status of the rear backrest inclination switch and the status of the rear backrest lock switch directly and then transmits the status of the respective backrest via interior CAN, electronic ignition lock control unit and user interface CAN to the instrument cluster.

Model 205.2, 253

with code 242 (Front passenger seat, electrically adjustable with memory function)

Model 205.2, 253

with code 275 (Memory package)

Collision avoidance:

If, when folding down the respective backrest, a risk of collision exists with the driver or front passenger seat, this is then adjusted accordingly.

	Electrical function schematic for rear passenger compartment backrest release		PE91.29-P-2060-97FBA
	Overview of system components, electric seats		GF91.29-P-9992RF