Rear control panel control unit, component description - GF83.40-P-3020GMB

MODEL 164.1 as of model year 09/YoM 08 model refinement package with CODE (581) Comfort automatic air conditioning

MODEL 164.8, 251.0/1 as of model year 09/YoM 08 with CODE (581) Comfort automatic air conditioning

Shown on model 251 without code (494) USA version with code (519) Rear audio system and with code (872) Electric seat heater for left and right rear seats

Fig 1: Identifying Rear Control Panel Control Unit Component - Shown On Model 251

Courtesy of MERCEDES-BENZ USA

Location

The RCP [HBF] control unit is located in the extension of the center console in the 2nd seat row.

Shown on model 251 with code (494) USA version, with code (519) Rear audio system and with code (872) Electric seat heater for left and right rear seats

Fig 2: RCP (HBF) Control Unit Component Location

Courtesy of MERCEDES-BENZ USA

Location

The RCP [HBF] control unit is located in the extension of the center console in the 2nd seat row.

Design

The RCP [HBF] control unit includes the following control and display elements:

Left headphones volume control (1)
(with code (519) Rear audio system)
Increase air volume button (2)
Air volume indicator (3)
Temperature selector wheel (4)
AUTO button (5)
Headroom air distribution button (6)
Right headphones volume control (7)
(with code (519) Rear audio system)
Right headphones connector jack (8)
(with code (519) Rear audio system)
Footwell air distribution button (9)
OFF button (10)
Reduce air volume button (11)
Left headphones connector jack (12)
(with code (519) Rear audio system)
Button for seat heater in 2nd seat row, left (13)
(with code (872) Electrically heated left and right rear seats)
Button for seat heater in 2nd seat row, right (14)
(with code (872) Electrically heated left and right rear seats)

Task

The RCP [HBF] control unit has the following tasks:

Operation of the rear air conditioning
Reading in of signals
Actuation of components

Operation of the rear air conditioning

The RCP control unit allows the following actions:

Switching the temperature control ON and OFF
Interior temperature selection for the rear area
Manual blower control
Manual air distribution

Automatic blower control and air distribution
Separate left and right headphones volume control
(with code (519) Rear audio system)
Separately regulated left and right seat heaters
(with code (872) Electric seat heater for left and right rear seats)

The cooling and heat output is increased in the rear area by the rear air conditioning (model 164.8 and model 251 with code (582) Rear air conditioning).

It is operated with the following buttons, rotary switches and the selector wheel:

Temperature selector wheel
Air volume buttons
AUTO button
OFF button
Air distribution buttons
Headphones volume control (with code (519) Rear audio system)
Seat heater buttons (with code (872) Electrically heated left and right rear seats)

Temperature selector wheel

The desired specified temperature for the rear compartment can be set by turning the temperature selector wheel.

The selected specified temperature is displayed via LEDs at the border of the temperature selector wheel.

Air volume buttons

Pressing the respective air volume button enables the volume of air flowing into the rear area to be set manually.

An LED in the air volume display lights up.

Pressing repeatedly permits the air volume that is introduced into the vehicle interior to be increased.

The greater the requested air volume, the more LEDs that light up.

AUTO button

The air volume and the air distribution are regulated automatically when the AUTO button is pressed.

If the automatic operation is activated, the LED in the AUTO button lights up.

OFF button

The temperature control in the rear can be switched off completely or switched back on by pressing the OFF button. The rear shut-off flap is opened or closed accordingly.

The LED lights up when the temperature control is switched off.

Air distribution buttons

Pressing the respective air distribution button enables the distribution of the air flowing into the rear area to be set manually.

When the function is activated, the LED illuminates.

Headphones volume control

The requested volume of the headphones can be selected by turning the particular volume control. The volume can be regulated separately for left and right.

Seat heater buttons

The heat output for the relevant side can be regulated in three stages by pressing the relevant seat heaters button.

The particular button signal is transmitted via interior CAN to the seat heater, seat ventilation and steering wheel heater control unit (N25/7).

Reading in of signals

The input factors are read in with the following connections:

Direct line
Interior CAN

Direct line

The following signals are read in via a direct line:

Left audio input (with code (519) Rear audio system)
Right audio input (with code (519) Rear audio system)

Interior CAN

The signals are read in by the rear control panel control unit via the interior CAN. The resulting functions are described in the relevant function descriptions (see block diagram or function schematic).

Actuation of components

The actuation of the components takes place via the following connections:

Direct line
Interior CAN

Direct line

The following components are actuated:

Left headphones connector jack
(with code (519) Rear audio system)
Right headphones connector jack
(with code (519) Rear audio system)
Left headphones volume control
(with code (519) Rear audio system)
Right headphones volume control
(with code (519) Rear audio system)

Interior CAN

The signals are transmitted by the rear control panel control unit via the interior CAN. The resulting functions are described in the relevant function descriptions (see block diagram or function schematic).

	Wiring diagram for rear control panel control unit	Model 164	PE54.21-P-2125-99MAA
		Model 251	PE54.21-P-2125-99RAA