Electrical seat adjustment (ESA) - GF91.29-P-0009RFB

MODEL 205, 253 with CODE 221 (Electrically adjustable left driver seat) with CODE 222 (Electrically adjustable right front seat) without CODE 275 (Memory package)

Fig 1: Electrical Seat Adjustment (ESA) - Block Diagram

Courtesy of MERCEDES-BENZ USA

Function requirements, general

No overvoltage or undervoltage

Electrical seat adjustment (ESA), general

The ESA enables the electrical adjustment of the driver and front passenger seat. The driver and front passenger seat can be adjusted as follows:

Seat fore/aft position
Backrest inclination
Seat height
Seat inclination

The ESA function comprises the following subfunctions:

Function sequence for manual seat adjustment
Function sequence for antilock device

Function sequence for manual seat adjustment

The manual setting is made with each front switch group, seat adjustment. Operation of the front switch group, seat adjustment is read in over each front door LIN by the respective front door control unit. The respective front door control unit sends the adjustment requests via interior CAN, rear SAM control unit and heater LIN to the driver seat control unit or to the front passenger seat control unit. To adjust, hold down the switches in the front switch group, seat adjustment until the desired position is reached.

The driver seat control unit or the front passenger seat control unit actuates the following seat adjustment motors directly depending on the request:

Seat adjustment motor, seat fore/aft adjustment
Seat adjustment motor, backrest inclination
Seat adjustment motor for seat inclination adjustment
Seat adjustment motor for seat height adjustment

Function sequence for antilock device

The driver seat control unit or the front passenger seat control unit continuously monitors the power consumption of the seat adjustment motors. If the power consumption is too high (e.g. seat adjustment blocked), the driver seat control unit or the front passenger seat control unit switches the corresponding seat adjustment motor off.

	Electrical function schematic for seat adjustment (ESE)		PE91.29-P-2059-97FBC
	Overview of system components, electric seats		GF91.29-P-9992RF