Air-Recirculation Mode, Basic Function - GF83.40-P-1002A
Model all (CAR)
Overview
This document contains information on:
- General
- Function requirements
- Air recirculation mode via the air recirculation mode button
- Automatic air recirculation mode
- Pollutant-controlled air recirculation mode
- Continuous air-recirculation mode
General
In air-recirculation mode, the fresh air supply is switched off. To do so, the fresh/recirculated air flap closes and the air circulates in the vehicle interior. Air-recirculation mode is controlled via the climate control system.
Air-recirculation mode can be activated in the following ways:
- Manually by the user (e.g. for unpleasant odors)
- Automatically (e.g. for high pollutant concentration)
To prevent the windows from fogging, the system automatically switches back to fresh air mode after a period of time.
Function requirements
- Circuit 15 ON
- Climate control switched on
Air recirculation mode via the air recirculation mode button
Air-recirculation mode can be switched on and off manually on the air conditioning control panel. The LED in the air recirculation mode button lights up during air recirculation mode.
If the air recirculation button is pressed for longer than approx. 2 s, the side windows and the sliding sunroof or panoramic sliding sunroof are additionally closed. If the air recirculation button is pressed again for longer than approx. 2 s, these move back to the previous position (depending on market).
Depending on the outside temperature and the operating mode, the time until the system switches back to fresh air mode varies:
- After 5 min at outside temperatures below 5°C
- After 5 min, if the refrigerant compressor is switched off.
- After 30 min at outside temperatures above 5°C and refrigerant compressor switched on
Automatic air recirculation mode
The climate control system can automatically switch on the air-recirculation mode under certain conditions (the LED in the air-recirculation mode button does not light up in this case):
- If the outside temperature exceeds a certain threshold value.
- If the vehicle drives into a tunnel (only on vehicles with navigation i system).
In this case, the side windows and the sliding sunroof or panoramic sliding sunroof are additionally closed. The corresponding signals are received by the climate control system from the multimedia system control system.
- When the washing facility mode is switched on (depending on the equipment installed).
- If a thermal event is detected (for hybrid vehicles and vehicles with electric drive or with 48V technology).
Automatic air recirculation mode is active for max. 30 min.
Pollutant-controlled air recirculation mode
Additional function requirements:
- Refrigerant compressor switched on
- Defrosting function not active
With the aid of the air quality sensor, the climate control system monitors the concentration of poisonous carbon monoxide and nitrogen oxides in the incoming air. Depending on the equipment, the climate control system monitors the fine particle content of the incoming air with help from the fine particle sensor. As of a certain pollutant concentration it automatically switches to air-recirculation mode. The LED in the air-recirculation mode button does not light up in this case.
If, after starting the engine, the conditions for pollutant-controlled air-recirculation mode exist, the climate control system switches to air-recirculation mode in stages:
- Fresh air mode for approx. 30 s
- Air-recirculation mode with 80 % for approx. 10 s
- Air-recirculation mode with 100 % (as required)
The pollutant-controlled air-recirculation mode is active for a maximum of 30 minutes.
Depending on the model, the recirculated air status and the pollutant values can be shown on the media display.
Continuous air-recirculation mode
Depending on the model and equipment installed, it is possible to select between continuous air-recirculation mode and normal operation in the multimedia system menu. When the continuous air-recirculation mode function is activated, a warning is issued about an increased risk of fogging.
| Function schematics | |||
| Function schematic for regulating air-recirculation mode | Model 118, 177, 243, 247 | PE83.40-P-2501-97A | |
| Model 167 | PE83.40-P-2501-97B | ||
| Model 223 | PE83.40-P-2501-97C | ||
| Model 293 | PE83.40-P-2501-97D | ||
| Model 213, 238, 257, 290 as of model year 2021 | PE83.40-P-2501-97E | ||
| Model 206 | PE83.40-P-2501-97F | ||
| Model 295, 297 | PE83.40-P-2501-97G | ||
| Model 232 | PE83.40-P-2501-97H | ||
| Further basic functions | |||
| Washer system mode, basic function | GF82.90-P-9903A | ||
| Preventive occupant protection system, basic function | Model 118, 177, 206, 243, 247, 297 with code 299 (PRE-SAFE®) Model 167, 223, 293 Model 213 as of model year 2021 with code 299 (PRE-SAFE®) |
GF91.40-P-9900A | |
| Components | |||
| Air quality sensor, basic function | Model all (CAR) with code 581 (Automatic climate control) Model all (CAR) with code 830 (China version) |
GF83.40-P-2022A | |
| Fine particle sensor, basic function | Model all (CAR) with code 830 (China version) with code P53 (Air cleaning package) |
GF83.40-P-2023A | |
| Component descriptions | |||
| Component description for air divert switchover valve | Model 223 | GF07.05-P-3105A | |
| Component description for air pump switchover valve | Model 223 with engine 279 | GF14.30-P-2020A |