A/C System - Front Passenger Compartment Overview
A/C System - Front Passenger Compartment Overview
Component Group 1 - Left Side Of Passenger Compartment
1 16-pin Connector (T16) - Diagnostic Connection
• Perform A/C system on board diagnostic using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
2 Left Instrument Panel Vent (With Position Sensor In Left Side Vent (G628) )
• In the Comfort version with position sensor in left side vent. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• After replacement of the instrument panel vent, adapt the Climatronic control module (J255) , in order to adapt the end positions at the potentiometer, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
3 Vehicle Electrical System Control Module (J519)
• The various components (for example, of the A/C compressor regulator valve (N280) , etc.) are actuated by the A/C system via the vehicle electrical system control module.
4 Left Vent Temperature Sensor (G150)
• Removing and installing, refer to => [ Left Vent Temperature Sensor (G150) ] Left Vent Temperature Sensor (G150).
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
5 Defroster Vent For Left Side Window
6 Outside Air Temperature Display (G106)
• Part of the Instrument cluster control module (J285)
• In the case of an incorrect temperature display read measured values of the temperature sensor using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function, A/C system, instrument cluster.
• In the case of an incorrect measured value of the Outside air temperature sensor (G17), a problem in the A/C system control can occur. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
7 Instrument Cluster
• With the Instrument cluster control module (J285), Outside air temperature display (G106)
• The instrument cluster control module evaluates the measured value of the outside air temperature sensor and transmits it to the control head, the Climatronic control module (J255) via the data bus system. For testing, read measured values using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• In the case of an incorrect temperature display read measured values of the temperature sensor using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
8 Left Center Instrument Panel Vent (With Position Sensor In Left Center Vent (G626) )
• In the Comfort version with position sensor in left center vent. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• After replacement of the instrument panel vent, adapt the Climatronic control module (J255) , in order to adapt the end positions at the potentiometer, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
9 Front Information Display Control Head (J685)
• Multi Media Interface (MMI) display.
• Different versions. Refer to Electronic Parts Catalog (ETKA).
• Functions selected on the Climatronic control module (J255) (and various additional A/C system functions) are shown on the MMI display. Refer to Infotainment/MMI operating instructions.
10 Infrared Sensor For Temperature and Sunlight
• Shared component with the control head, cannot be replaced individually.
• Determines the temperature and the solar radiation on the Climatronic control module (J255).
• If the infrared sensor is covered or dirty, it cannot deliver correct measured values and the A/C system control is faulty.
• Check the measured value using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• The figure shows the Comfort version of the control head.
11 A/C System Control Head
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Climatronic Control Module (J255)
• The figure shows the Comfort version of the control head
• General information, refer to => [ Climatronic Control Module (J255) ] Description and Operation.
• Removing and installing, refer to => [ Climatronic Control Module (J255) ] Service and Repair.
12 Multimedia Control Head (E380)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Using the "Car"/"Car systems" button, additional A/C system functions can be called up and their settings changed. Refer to Infotainment/MMI operating instructions.
• For the various functions of the A/C system to be able to be selected and displayed on the Multi Media Interface (MMI) display, the correct version of the Climatronic control module (J255) , must be installed, coded, and adapted.
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
13 Fresh Air Blower (V2)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• With Fresh air blower control module (J126).
• Removing and installing, refer to => [ Fresh Air Blower (V2) with Fresh Air Blower Control Module (J126) ] Fresh Air Blower (V2) With Fresh Air Blower Control Module (J126).
14 A/C Unit (View From Left)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Air distribution system block diagram, refer to => [ Air Routing and Air Distribution Components ] Air Routing and Air Distribution Components.
• Overview:
• Basic version, refer to => [ Basic Version - Add On Parts of A/C Unit Overview ] Basic Version - Add On Parts of A/C Unit Overview.
• Comfort version, refer to => [ Comfort Version - Add On Parts of the A/C Unit Overview ] Comfort Version - Add On Parts of the A/C Unit Overview.
15 Left Footwell Vent Temperature Sensor (G261)
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Removing and installing, refer to => [ Left Footwell Vent Temperature Sensor (G261) ] Left Footwell Vent Temperature Sensor (G261).
16 Left Condensation Water Drain
• Checking, refer to => [ Checking the Condensation Water Drain Hose ] Checking the Condensation Water Drain Hose.
• Removing and installing, refer to => [ Condensation Water Drain Hose ] Service and Repair.
17 Left Front Seat
• Depending on the equipment with seat heating, seat ventilation.
• Different versions, refer to Electronic Parts Catalog (ETKA).
• The seat heating, seat ventilation setting is made at the Climatronic control module (J255). Check the actuation in "Read measured values" using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Seat heating and seat ventilation are activated via various control modules. Refer to and Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• For information about seat heating and seat ventilation, refer to => [ Seat Heating and Ventilation, Checking ] Seat Heating and Ventilation, Checking.
• Repair seat heating and seat ventilation.
18 Accelerator Mechanism
• Kick-down switch off of the A/C compressor (via the A/C compressor regulator valve (N280) ) is performed upon request from the engine control module (the data is exchanged via the data bus).
• To check the current status check"Read measured values" (for the A/C system and the particular engine control module) using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
Component Group 2 - Right Side Of Passenger Compartment
1 A/C Unit (View From Right)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Air distribution system block diagram, refer to => [ Air Routing and Air Distribution Components ] Air Routing and Air Distribution Components.
• Overview:
• Basic version, refer to => [ Basic Version - Add On Parts of A/C Unit Overview ] Basic Version - Add On Parts of A/C Unit Overview.
• Comfort version, refer to => [ Comfort Version - Add On Parts of the A/C Unit Overview ] Comfort Version - Add On Parts of the A/C Unit Overview.
2 Right Front Seat
• Depending on the equipment with seat heating, seat ventilation.
• Different versions, refer to Electronic Parts Catalog (ETKA).
• The seat heating, seat ventilation setting is made at the Climatronic control module (J255). Check the actuation in "Read measured values" using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Seat heating and seat ventilation are activated via various control modules. Refer to and Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• For information about seat heating and seat ventilation, refer to => [ Seat Heating and Ventilation, Checking ] Seat Heating and Ventilation, Checking.
• Repair seat heating and seat ventilation.
3 Right Instrument Panel Vent (With Position Sensor In Right Side Vent (G629) )
• In the Comfort version with position sensor in right side vent. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• After replacement of the instrument panel vent, adapt the Climatronic control module (J255) , in order to adapt the end positions at the potentiometer using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
4 Right Center Instrument Panel Vent (With Position Sensor In Right Center Vent (G627) )
• In the Comfort version with position sensor in right center vent. Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• After replacement of the instrument panel vent, adapt the Climatronic control module (J255) , in order to adapt the end positions at the potentiometer, using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
5 Air Humidity Sensor (G355)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Installed in the mirror base.
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
6 Sunlight Photo Sensor (G107)
• Different versions, refer to Electronic Parts Catalog (ETKA).
• To check the solar radiation measured by the sunlight photo sensor and calculated by the Climatronic control module (J255) "Read measured values" using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Removing and installing, refer to => [ Sunlight Photo Sensor (G107) ] Service and Repair.
7 Windshield Defroster Vent
8 Defroster Vent For Right Side Window
9 Right Vent Temperature Sensor (G151)
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Removing and installing, refer to => [ Right Vent Temperature Sensor (G151) ] Right Vent Temperature Sensor (G151).
10 Evaporator Vent Temperature Sensor (G263)
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Removing and installing, refer to => [ Evaporator Vent Temperature Sensor (G263) ] Evaporator Vent Temperature Sensor (G263).
11 Air Duct For Glove Compartment Cooling
• Only in the Comfort version.
• Removing and installing, refer to => [ Air Duct For Glove Compartment Cooling ] Air Duct For Glove Compartment Cooling.
12 Dust and Pollen Filter
• Different versions, refer to Electronic Parts Catalog (ETKA).
• Follow the replacement intervals.
• Removing and installing, refer to => [ Dust and Pollen Filter ] Service and Repair.
13 Dust and Pollen Filter Shaft Cover
14 Right Condensation Water Drain
• Checking, refer to => [ Checking the Condensation Water Drain Hose ] Checking the Condensation Water Drain Hose.
• Removing and installing, refer to => [ Condensation Water Drain Hose ] Service and Repair.
15 Right Footwell Vent Temperature Sensor (G262)
• Check using the Vehicle Diagnostic Tester in the "Guided Fault Finding" function.
• Removing and installing, refer to => [ Right Footwell Vent Temperature Sensor (G262) ] Right Footwell Vent Temperature Sensor (G262).