Seat heater control unit, component description - GF91.30-P-5214RF

Model 205, 253 with code 401 (Climatised front seats) except code 221 (Electrically adjustable left driver seat) except code 222 (Electrically adjustable right front seat) except code 242 (Front passenger seat, electrically adjustable with memory function) except code 275 (Memory package)

Model 205, 253 with code 872 (Heated rear seats)

Model 205, 253 with code 873 (Seat heating for driver and front passenger) except code 221 (Electrically adjustable left driver seat) except code 222 (Electrically adjustable right front seat) except code 242 (Front passenger seat, electrically adjustable with memory function) except code 275 (Memory package)

With code 401 (Seat climate control for driver and front passenger) or with code 873 (Seat heater for driver and front passenger)

Fig 1: Identifying Front Passenger And Driver Seat Heater Control Unit

Courtesy of MERCEDES-BENZ USA

The front seat heater control unit in the front passenger seat functionally replaces the driver seat heater control unit and the front passenger seat heater control unit. In the following sections, only the term "seat heater control unit" is used.

With CODE 872 (Seat heater in rear), shown on model 205.1

Fig 2: Identifying Rear Seat Heaters Control Unit - Shown On Model 205.1

Courtesy of MERCEDES-BENZ USA

Location

With code 401 (Seat climate control for driver and front passenger) or with code 873 (Seat heater for driver and front passenger):

The seat heater control unit is located on the seat frame of the respective front seat (up to 31.05.2015) or on the seat frame of the front passenger seat (as of 01.06.2015).

With CODE 872 (Seat heater in rear):

The rear seat heater control unit is located in the center under the rear bench.

Tasks

The seat heater control unit has the following tasks:

Control of the seat heater
Control of the seat ventilation (with CODE 401 (Seat climate control for driver and front passenger))

The tasks are subdivided as follows:

Reading in of signals
Evaluation of input factors
Actuation of components
Transmitting signals

Reading in of signals

The seat heater control unit reads in the following signals via the heater LIN (LIN B28):

Seat heater request
Seat ventilation request with CODE 401 (Seat climate control for driver and front passenger))

Evaluation of input factors

The input factors that have been read in are evaluated by the seat heater control unit and the relevant components are then actuated.

Actuation of components

The seat heater control unit (with code 401 (Seat climate control for driver and front passenger) or with code 873 (Seat heater for driver and front passenger)) actuates the following components via direct lines:

Left front seat cushion seat ventilation motors (M18/9) (with CODE 401 (Seat climate control for driver and front passenger))
Left front backrest seat ventilation motors (M18/10) (with CODE 401 (Seat climate control for driver and front passenger))
Right front seat cushion seat ventilation motors (M18/11) (with CODE 401 (Seat climate control for driver and front passenger))
Right front backrest seat ventilation motors (M18/12) (with CODE 401 (Seat climate control for driver and front passenger))
Left front seat cushion heater pad (R13/1)
Left front seat backrest heater pad (R13/2)
Right front seat cushion heater pad (R13/3)
Right front seat backrest heater pad (R13/4)

The rear seat heater control unit (with CODE 872 (Seat heater in rear)) actuates the following components via direct lines:

Left rear seat surface heater pad (R13/5)
Left rear backrest heater pad (R13/6)
Right rear seat surface heater pad (R13/7)
Right rear backrest heater pad (R13/8)

Transmitting signals

The seat heater control unit sends the following signals via the heater LIN:

Seat heater status
Seat ventilation status (with CODE 401 (Seat climate control for driver and front passenger))

	Wiring diagram for rear seat heater control unit	Model 205, 253 with code 872 (Heated rear seats)	PE91.30-P-2101-97FBA
	Wiring diagram for seat heater control unit	Model 205, 253 with code 401 (Climatised front seats) except code 221 (Electrically adjustable left driver seat) except code 222 (Electrically adjustable right front seat) except code 242 (Front passenger seat, electrically adjustable with memory function) except code 275 (Memory package) Model 205, 253 with code 873 (Seat heating for driver and front passenger) except code 221 (Electrically adjustable left driver seat) except code 222 (Electrically adjustable right front seat) except code 242 (Front passenger seat, electrically adjustable with memory function) except code 275 (Memory package)	PE91.30-P-2104-97FBA