gf9130p9900a

Seat heating, basic function

Type gf · topic 91.30 · version 0105 · 2020-06-27

Applies to: Model all (CAR) with code 401 (Climatised front seats) Model all (CAR) with code 402 (Rear seat climate control) Model all (CAR) with code 872 (Left and right rear seat heating) Model all (CAR) with code 873 (Left and right drivers seat heating) Model all (CAR) with code 886 (Seat heater for 3rd seat row) Model all (CAR) with code 902 (Seat heater Plus for driver and front passenger) Model all (CAR) with code 903 (Rear comfort seat heating)

Where it sits

Function group 3 Body › 91 Seats, bunks, restraint systems › 91.30 Seat heater, seat ventilation — Series 900 (models 9**) · Series 902 (models 9**) · Series 904 (models 918, 919, 924, 925, 938, 943, 957) · Series 906 (models 917, 918, 924, 953)

EinPAS 39 Heating/ventilation/cooling › 39.35 Seat heating/seat climate control/armrest heating › 39.35.1 Basic information — Series 900 (models 9**) · Series 902 (models 9**) · Series 904 (models 918, 919, 924, 925, 938, 943, 957) · Series 906 (models 917, 918, 924, 953)

Also applies to engines/gearboxes: 139 ***, 254 ***, 256 ***, 272 ***, 276 ***, 282 ***, 457 9**, 541 9**, 542 9**, 608 ***, 700 4**, 700 420, 700 421, 700 422, 700 423, 715 3**, 715 5**, 722 6**, 722 9**, 724 ***, 724 0**, 724 033, 724 044, 724 045, 724 1**, 724 103, 724 114, 724 115, 724 120, 725 ***, 725 0**, 725 035, 725 037, 725 038, 725 085, 725 1**, 739 390, 739 391, 739 395, 739 396, 739 397, 739 398, 739 399, 740 698, 743 3**, 743 4**, 743 498, 746 971, 924 9**, 924 910, 925 9**, 926 9**

GF91.30-P-9900A

Seat heating, basic function

23.06.2020

Model

all (CAR)

with code 401 (Climatised front seats)

Model

all (CAR)

with code 402 (Rear seat climate control)

Model

all (CAR)

with code 872 (Left and right rear seat heating)

Model

all (CAR)

with code 873 (Left and right driver's seat heating)

Model

all (CAR)

with code 886 (Seat heater for 3rd seat row)

Model

all (CAR)

with code 902 (Seat heater Plus for driver and front passenger)

Model

all (CAR)

with code 903 (Rear comfort seat heating)

Overview:

This document contains information on:

General

Function requirements

Front seat heater control

Seat heating control in rear passenger compartment

Manual switching on and off:

Reduced heating output with multiple activation.

Reduced heating output in ECO drive program.

Additional seat heater Plus functions

Actuation by other systems

General

The seat heating has the task of increasing the temperature of the seat cushion or seat backrest. The seat heating creates a more pleasant climate for vehicle occupants at low temperatures. The seat heating is performed via integrated heating elements in the seats.

Function requirements

Circuit 15 or circuit 15R ON

Only for front passenger seat heating:

Front passenger seat belt buckle contact (for approx. 15 minutes after change of circuit)

Front seat heater control

Depending on the equipment installed, one of the following control units actuates the seat heating:

Overview of front seats seat heating control

Installed control units/position of seat heating

Driver's seat heating

Front passenger seat heating

Without seat heating Plus

Without driver's seat control unit
Without front passenger seat control unit

Seat climate control control unit

Seat climate control control unit

With driver's seat control unit
Without front passenger seat control unit

Driver seat control unit

Driver seat control unit

With driver's seat control unit
With front passenger seat control unit

Driver seat control unit

Front passenger seat control unit

With seat heating Plus

Driver seat heater control unit (seat surface and seat backrest center section) and driver seat control unit (seat side bolsters)
or
Driver seat control unit

Front passenger seat heater control unit (seat surface and seat backrest center section) and front passenger seat control unit (seat side bolsters)
or
Front passenger seat control unit

Seat heating control in rear passenger compartment

Control of the seat heater is dependent on the equipment installed:

If the rear seat is equipped with a seat control unit, it controls the seat heating.

On rear seats without the seat control unit, a seat heater control unit is installed.

With seat heating Plus, the seat control unit is often supported by an additional seat heater control unit.

Manual switching on and off:

The seat climate control switch group is installed in the doors or on the side wall of the respective side of the vehicle. The seat climate control switch group records the control signals via the seat heater button and sends them to the control system.

The heating output can set to 3 different levels. The actuation of the heating elements is performed by means of pulse width modulation (PWM) and thus enables actuation in 3 intensity levels (100 % / 65 % / 35 % power).

The control system sends the stage setting of the seat heating back to the seat climate control switch group. This actuates the LEDs in the seat heating button accordingly.

The heating output of the individual stages is also adjusted depending on the outside temperature. The heating output settings of the respective heating levels can be adjusted via the diagnostic tester.

Depending on the equipment, it is also possible to operate the seat heating in the rear passenger compartment via the vehicle's own tablet PC or the rear touchscreen.

Reduced heating output with multiple activation

If the seat heating is selected again with the same circuit status, the seat heating actuates heating level 3 at only 90  % of the heating output.

Reduced heating output in ECO drive program

If the ECO drive program is activated, the seat heating switches to a mode to reduce the operating current. This is done by means of reduced pulse-width modulated signals. The control system multiplies the individual output levels of the pulse width modulated signals by an ECO factor and thus reduces the heating output.

If the ECO drive program is deactivated, the seat heating automatically returns to the normal mode. On vehicles with seat heating Plus, this continues to regulate to the specified temperature, but with reduced PWM values at the output of the actuating control unit.

It is possible to adjust the ECO factors using the diagnostic tester.

Additional seat heater Plus functions

Additional temperature sensors are installed in the seat heating mats. To monitor the seat heating, the seat heating control reads in the signals from the corresponding heater pad temperature sensors directly and evaluates them. In line with this data and the set heating level, the seat heating Plus actuates the heater pads.

In addition, actuation is carried out depending on the vehicle interior temperature. This enables faster heating to be achieved. The lower the vehicle interior temperature, the faster the seat heating Plus heats up the heater pads.

Actuation by other systems

For actuation by other systems, the function requirement for circuit 15 or 15R ON does not apply. With circuit 30t, the other systems can also activate the seat heating.

The seat heating can also be actuated by the following systems:

Pre-air conditioning

Revitalization

Massage programs of multicontour seats

Function schematics

Function schematic for actuating front seat heating

Model 118, 177, 247 with code 401 (Climatised front seats)Model 118, 177, 247 with code 873 (Left and right driver's seat heating)

PE91.30-P-2502-97A

Model 167 with code 401 (Climatised front seats) except code 902 (Seat heater Plus for driver and front passenger)Model 167 with code 873 (Left and right driver's seat heating) except code 902 (Seat heater Plus for driver and front passenger)

PE91.30-P-2502-97B

Model 167 with code 902 (Seat heater Plus for driver and front passenger) except code 401 (Climatised front seats) except code 873 (Left and right driver's seat heating)

PE91.30-P-2502-97C

Model 213, 238, 257, 290 as of model year 2021 with code 873 (Left and right driver's seat heating)

PE91.30-P-2502-97E

Model 213, 238, 257, 290 as of model year 2021 with code 902 (Seat heater Plus for driver and front passenger)

PE91.30-P-2502-97F

Model 293 with code 401 (Climatised front seats)Model 293 with code 873 (Left and right driver's seat heating)

PE91.30-P-2502-97D

Function schematic for actuating rear seat heating

Model 167 with code 872 (Left and right rear seat heating) except code 886 (Seat heater for 3rd seat row)

PE91.30-P-2503-97A

Model 167 with code 886 (Seat heater for 3rd seat row)

PE91.30-P-2503-97B

Model 167 with code 903 (Rear comfort seat heating) except code 872 (Left and right rear seat heating) except code 886 (Seat heater for 3rd seat row)

PE91.30-P-2503-97H

Model 213 as of model year 2021 with code 872 (Left and right rear seat heating) except code 223 (Electric backrest adjustment and head restraints)Model 238, 257, 290 as of model year 2021 with code 872 (Left and right rear seat heating)

PE91.30-P-2503-97D

Model 213 as of model year 2021 with code 223 (Electric backrest adjustment and head restraints) with code 872 (Left and right rear seat heating)Model 213 as of model year 2021 with code 903 (Rear comfort seat heating)

PE91.30-P-2503-97E

Model 293 with code 872 (Left and right rear seat heating)

PE91.30-P-2503-97C

Further basic functions

Seat climate control timer-controlled shutoff, basic function

GF91.30-P-1000A

Seat climate control automatic shutoff, basic function

GF91.30-P-1001A

Control units

Seat control unit, basic function

Vehicles with seat heating and electrical seat adjustment at front, vehicles with seat heating and electrical seat adjustment in rear passenger compartment

GF91.29-P-9890A

Seat climate control unit, basic function

Vehicles with seat heater and without electrical seat adjustment, vehicles with code 902 (Seat heater plus for driver and front passenger), vehicles with code 903 (Seat heater plus for rear outer seats)

GF91.30-P-9891A

Components

Tablet cradle electric controller unit, basic function

Vehicles with code 447 (Touchscreen in rear passenger compartment (rear touchscreen)) and seat heating in rear passenger compartment

GF54.21-P-2007A

Rear passenger compartment center console touchscreen, basic function

Model 290
as of model year 2021
with code 224 (Rear individual seat design)
with code 872 (Left and right rear seat heating)

GF54.21-P-2009A

Referenced documents