Ac in car stopped working
Why did my Mercedes AC suddenly stop working ?
Suddenly losing functionality in your Mercedes-Benz’s air conditioning system can be frustrating and inconvenient. Whether you’re driving on a hot summer day or facing unexpected discomfort, understanding the potential reasons behind this issue is essential. From electrical faults to refrigerant leaks, various factors can contribute to the sudden failure of your Mercedes AC system, impacting your driving experience. Let’s delve into the possible causes behind why your Mercedes AC suddenly stopped working.
How does Mercedes climate control work?
Operating Conditions of Automatic Air Conditioning
- Key in ignition
- Automatic air conditioner activated
- Engine running (except hybrid and electric vehicles; stay tuned)
- Refrigerant compressor engaged
Automatic climate control
The electronic regulation of temperature and air distribution in the cabin is carried out based on the settings selected on the automatic air conditioning control unit and keyboard, as well as the variables input by various sensors (e.g., interior temperature, exterior temperature, coolant temperature, vehicle speed). The determination of these variables is described below.
The automatic air conditioning control unit and keyboard are networked with the vehicle’s electronics via the CAN multiplexing network and the automatic air conditioning LIN network. This allows for the integration of important factors to improve regulation quality and reduce energy consumption.
When settings affecting temperature, air distribution, or air flow are adjusted on the automatic air conditioning control unit and keyboard, the corresponding adjustment values briefly appear on the vehicle’s central display.
How do I turn on AC on my Mercedes ?
N22/7 Automatic air conditioning control unit and keyboard
N22/7s1: Rear window heating button
N22/7s2: Air recirculation mode button
2: “A/C” button
3.1: Left temperature dial
3.2: Right temperature dial
8: “OFF” button
9: “RESET” button
10: “AUTO” button
11: “ZONE” button
12: Decrease airflow button
13: Increase airflow button
14: “MODE” button downwards
15: “MODE” button upwards
To turn on Ac in mercedes, follow the following steps;
- Turn the ignition to the ON position.
- Press the A/C button (Button 2).
- Start the engine.
- Adjust the temperature dial.
- Choose the desired airflow using buttons 12 and 13.
- Select the zone you want to cool/heat using button 11.
- If you want the cabin to be a single zone, press button 10.
How does ac compressor works ? Mercedes Compressor
The refrigerant compressor is responsible for drawing in and compressing the refrigerant fluid. The power of the refrigerant compressor is continuously regulated up to 100% by the automatic air conditioning control unit and keyboard via the refrigerant compressor regulating valve. The automatic air conditioning control unit directly activates the refrigerant compressor control valve.
In vehicles equipped with a refrigerant compressor with an electromagnetic clutch, an electromagnetic clutch is additionally mounted. With this clutch, the refrigerant compressor can be completely separated from the belt drive force. This allows for additional fuel savings. The automatic air conditioning control unit directly commands the electromagnetic clutch of the refrigerant compressor.
Additionally, the automatic air conditioning control unit sends the request for idle speed increase via the interior CAN to the ignition/starting switch control unit, and then to the engine control unit either for gasoline engine (M270 engine type. For more information on this engine, refer to the following link: Mercedes Engine type M270 Gasoline Mercedes A Class and Engine AMG 133) or for the CDI control unit (OM651 engine type. For more information on this engine, refer to the following link: Mercedes OM651 Engine in Mercedes A-Class 176).
In the case of the OM607 engine (For more information on this Renault engine, refer to the following link: Mercedes A-Class OM607 Engine), the automatic air conditioning control unit sends the request for idle speed increase through the interior CAN, electronic theft deterrent control unit (ignition/starting switch), the rolling gear train CAN to the powertrain control unit, and the powertrain CAN to the diesel engine control unit.
The diesel engine control unit or the gasoline engine control unit increases the idle speed based on the additional load occurring when the refrigerant compressor is engaged.
The refrigerant compressor can be engaged and disengaged using the “A/C” button or the “OFF” button on the automatic air conditioning control unit and keyboard.
Who controls the air conditioning compressor?
On the automatic air conditioning system of the Mercedes-Benz A-Class, the refrigerant compressor is directly activated by the A/C button on the automatic air conditioning control unit and keyboard.
2: Button to activate automatic air conditioning in the Mercedes
How to replace ac compressor ?
To replace the air conditioning compressor, you should follow the following steps;
- Drain the air conditioner
- Remove the cylinder head cover cover
- Loosen and remove the V-ribbed belt
- Unscrew the screw and remove the low pressure line from the refrigeration compressor
- Close the opening of the low pressure line and the refrigeration compressor with suitable plugs
- Unscrew the screw and remove the high pressure line from the refrigeration compressor
- Close the orifice of the high pressure line and the refrigeration compressor
- Unlock and disconnect the electrical connector from the refrigeration compressor
- Unscrew the screw and remove the hose support
- Support the refrigeration compressor to prevent it from falling
- Unscrew the screws, Refrigeration compressor screw on component support
- Remove the refrigeration compressor from the engine compartment by working upwards
How to fix my cars Ac ?
Why is my Mercedes AC blowing hot air ?
Functional sequence of air guide flap control
The distribution of air in the cabin is controlled by adjusting the air guidance flaps in the air conditioning unit. The following components are operated by the automatic air conditioning control unit and keyboard through the air conditioning LIN:
- Fresh/recirculated air flap controlled by the fresh/recirculated air flap servo motor (fresh/recirculated air regulation and dynamic air regulation)
- Left mixed air flap controlled by the left mixed air flap servo motor (left temperature regulation)
- Right mixed air flap controlled by the right mixed air flap servo motor (right temperature regulation)
- Air distribution flap controlled by the central air distribution flap servo motor (blower regulation)
The position of the air distribution flap is detected by the position detection micro-switch for the central air distribution flap. The state of the micro-switch is directly received by the automatic air conditioning control unit and keyboard. If an incorrect position is detected, the position of the air distribution flap is post-regulated by the automatic air conditioning control unit and keyboard using the central air distribution flap servo motor.
If one of the blend door actuators, responsible for regulating the mixture between hot and cold air within the ventilation housing inside the dashboard, is damaged, it can result in the direct flow of hot air into the cabin. This can cause excessive heat sensation or a lack of control over the interior temperature of the car. In such cases, it is important to have the ventilation system inspected and repaired by a professional to ensure optimal operation of the air conditioning system.