Audi A4: Heating, Ventilation & Air Conditioning
Audi A4 (B9) 2016-2026 Service Manual / Heating, Ventilation & Air Conditioning
- Warnings when Working on Vehicles with High Voltage System
- A/C System, General Information
- Introduction
- A/C Technology Basic Principles
- Refrigerant R134a
- Refrigerant R134a Characteristics
- Refrigerant Oil
- A/C System Operation
- General Safety Precautions
- A/C System and Refrigerant R134a Safety Precautions
- Refrigerant Circuit, General Precautions
- Refrigerant Circuit General Information
- Vehicles with a High Voltage System (Hybrid Vehicles)
- Refrigerant Circuit Components Allocation, High and Low Pressure Sides
- Refrigerant Circuit
- Connections for Quick-Release Coupling on Refrigerant Circuit
- Switches and Sensors on Refrigerant Circuit and Connections
- Refrigerant Circuit Pressures and Temperatures
- Pressure Gauge, Tests and Measurements
- Service and Recycling Units
- Laws and Regulations
- Refrigerant Circuit
- A/C System Repair Information
- Using Service Station
- Refrigerant Circuit, Flushing with Compressed Air and Nitrogen
- Refrigerant Circuit, Cleaning (Flushing), with Refrigerant R134a
- Refrigerant Circuit, Determining Leaks
- Refrigerant Circuit Complaints
- A/C Service Station, Connecting
- General Information
- Service Station, Connecting with Connections on Low- and High Pressure Side of Refrigerant Circuit
- Service Station, Connecting with No Connection on Low- and High Pressure Side of Refrigerant Circuit
- Pressures, Checking
- General Information
- Refrigerant Circuit, Checking Pressure with Service Station
- Checking Pressures for Vehicles with Restrictor and Reservoir (with Internally Regulated Compressor)
- Checking Pressures on Vehicles with Expansion Valve and Receiver/Dryer (with Internally Regulated Compressor)
- Vehicles with Restrictor, Reservoir and A/C Compressor Regulator Valve -N280- (Externally Regulated A/C Compressor), Checking Pressures
- Vehicles with Restrictor, Receiver/Dryer and A/C Compressor Regulator Valve -N280-, Checking Pressures, Externally Regulated Compressor
- Checking Pressures on Vehicles with Electrically Driven A/C Compressor (Vehicles with Hybrid Drive)
- Refrigerant Circuit Components, Replacing
- General Information
- Leaking or Damaged Components except A/C Compressor, Reservoir or Receiver/Dryer
- Compressor, Replacing without the Need for Flushing Refrigerant Circuit
- Compressor, Replacing on Account of Leakage or Internal Damage
- Receiver/Dryer or Accumulator and Restrictor, Replacing after Cleaning Refrigerant Circuit
- A/C Compressor Regulator Valve -N280-, Removing and Installing
- Refrigerant R134a Capacities, Refrigerant Oil and Approved Refrigerant Oils
- Tools and Equipment
READ NEXT:
Warnings when Working on Vehicles with High Voltage System
Vehicles with a High-Voltage System (Hybrid Vehicles)
Working on Vehicles with High-Voltage System (Hybrid Vehicles)
Extremely Dangerous Due to High-Voltage
The high-voltage system is under high-volta
Introduction
The purpose of this repair manual is to provide service
advisors and technicians with the basic knowledge needed to
ensure professional and competent procedures.
Note
Only the careful study
SEE MORE:
Cruise control system
Description
Applies to: vehicles with cruise control system
The cruise control system assists the driver in
maintaining a constant speed above approximately
15 mph (20 km/h). The system maintains
the desired speed by braking and accelerating.
WARNING
Observe the safety precautions and note the
Refrigerant Circuit, Checking Pressure with Service Station
General Information
Note
All test conditions marked * are vehicle-specific and are
described in the Repair Manual for the relevant vehicle.
Check cooling performance.
Connections with valve and service connections for
measurement and testing. Refer to
→ Heating, Ventilation and
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