2012 AUDI S4 B8 Service and Repair Manual

2009-2016 AUDI S4 SERVICE AND REPAIR MANUAL

HVAC Air Conditioning (Sedan) 87 AIR CONDITIONING GENERAL INFORMATION A/C AND REFRIGERANT SAFETY PRECAUTIONS The assemblies and piping system of the air conditioner are filled with the following refrigerant: 1.1.1.2 Tetrafluorethane(CF 3 -CH 2 F or CH 2 F-CF 3 ) Currently, this refrigerant is known under the following trade names R134a, H-FKW 134a, SUVA 134a and KLEA 134a (other trade names may be used in other countries). z Safety Precautions, handling refrigerant, refer to SAFETY PRECAUTIONS WHEN HANDLING REFRIGERANT . z Safety Precautions When Working on Vehicles with Start/Stop System, refer to SAFETY PRECAUTIONS WHEN WORKING ON VEHICLES WITH START/STOP SYSTEM . z Discharge refrigerant circuit according to REFRIGERANT CIRCUIT, DRAINING . z Working on Refrigerant Circuit. Refer to REFRIGERANT CIRCUIT REPAIR . z Vehicles with A/C, Painting. Refer to VEHICLES WITH A/C, PAINTING . z A/C System, Additional Information. Refer to REFRIGERANT CIRCUIT REPAIR . SAFETY PRECAUTIONS WHEN HANDLING REFRIGERANT The following safety measures should be observed for this refrigerant (additional guidelines apply in individual countries). If is necessary to open the refrigerant circuit during service work, discharge the refrigerant circuit first according to REFRIGERANT CIRCUIT, DRAINING . In doing so, the utmost care is to be taken to avoid contact with liquid refrigerant or refrigerant vapors. Should refrigerant nevertheless escape, avoid inhaling the WARNING: Keep an eye bath to hand. If liquid refrigerant has come in contact with your skin and eyes, immediately flush with cool water for 15 minutes. Then apply eye drops and consult a doctor immediately even if no pain is felt. The doctor must be informed, which type of refrigerant caused the freezing. 2012 Audi S4 HVAC Air Conditioning (Sedan)

resultant refrigerant/air mixture. Extraction systems are therefore to be switched on and use made of both rubber gloves and protective goggles. Reason: Intensive exposure to refrigerant on unprotected parts of the body will result in frostbite. Should refrigerant come into contact with other parts of the body despite compliance with all the pertinent safety measures, these are similarly to be rinsed thoroughly in cold water without delay for at least 15 minutes. Although refrigerant does not represent a fire hazard, smoking, welding, soldering and brazing are not permitted in areas exposed to refrigerant. Reason: The high temperature of a naked flame or hot objects causes decomposition of refrigerant gas. Inhalation of the resultant toxic decomposition products leads to dry coughing and nausea. SAFETY PRECAUTIONS WHEN WORKING ON VEHICLES WITH START/STOP SYSTEM REFRIGERANT CIRCUIT REPAIR z Appropriate current flow diagrams can be found in Current Flow Diagrams, Electrical Fault Finding and Fitting Locations binder. refer to appropriate SYSTEM WIRING DIAGRAM. z A data plate in engine compartment indicates the refrigerant used and capacity. z Additional information for repairs on vehicles with an A/C system and for handling refrigerant can be found in General Information . Work on refrigerant system should only be performed in a ventilated rooms (workshops). Ensure that within 5 meters circumference are no working-pits, basement staircases or shafts. Extraction systems are to be switched on. Reason: WARNING: On vehicles with the Start/Stop System, the engine could start automatically causing serious personal injury. z If the Start/Stop System is activated (recognizable by a message in the instrument cluster), it is possible to start the engine automatically. z Make sure the Start/Stop System is deactivated is deactivated (ignition switched off) whenever working on the vehicle. WARNING: Before working on electrical system (wiring), remove relevant fuse(s). 2012 Audi S4 HVAC Air Conditioning (Sedan)

The refrigerant emerging is not only colorless and odorless, but also heavier than air and thus displaces oxygen. If refrigerant gas does escape even though all the safety precautions have been followed, there is a risk of suffocating in poorly ventilated areas and in workshop pits - even if it is not noticeable. Do not attempt repair on filled air conditioning systems by soldering, brazing or welding. This pertains also for welding and soldering work on the vehicle, in the event that parts of the climate control system may heat up Reason: Exposure to heat creates considerable pressure in the system, which could cause it to burst. Corrective action: Discharge refrigerant circuit according to REFRIGERANT CIRCUIT, DRAINING . When servicing air conditioner, all open components and pipe connections are to be immediately re-sealed. Reason: Moisture will enter into air conditioner components if they are left open for a lengthy period. If this is the case, air conditioners cannot be refilled without having to replace parts of the system. The A/C refrigerant system may be drained and opened only if it is for safety reasons, refer to A/C AND REFRIGERANT SAFETY PRECAUTIONS or if components of the A/C refrigerant system must be replaced, refer to REFRIGERANT CIRCUIT, DRAINING . When performing all other usual vehicle repair work, the refrigerant circuit of the A/C system should remain closed. Repairs to the heating and A/C without opening the refrigerant circuit are possible and are described in this Repair information, refer to REFRIGERANT CIRCUIT COMPONENTS OVERVIEW , A/C SYSTEM CONTROL AND REGULATION COMPONENTS OUTSIDE PASSENGER COMPARTMENT and A/C SYSTEM CONTROL AND REGULATION COMPONENTS INSIDE PASSENGER COMPARTMENT . NOTE: The escaping refrigerant/air mixture should not be inhaled, but should be sucked out via an existing exhaust ventilation system. NOTE: Parts on the A/C that are damaged or leaking cannot be welded or soldered. They must be replaced. NOTE: Disconnect Battery before starting electric welding work on vehicle. Refer to [For engine(s) CAEB, CALA, CCBA] Removal and Installation . NOTE: The connections for the senders/switches described in this Workshop information are fitted with a valve which closes automatically when the 2012 Audi S4 HVAC Air Conditioning (Sedan)

Service work on the A/C system that requires the refrigerant circuit to be discharged and thus cannot be performed in every Audi workshop are described from COOLANT CIRCUIT, SERVICING . Certain tools are required to discharge the refrigerant circuit, these work procedures must only be performed by trained personnel as well. Therefore, bring vehicle to a workshop that has the necessary tools and in which the work can be performed accordingly by qualified personnel if necessary. Refer to General Information . z Contact corrosion. Refer to CONTACT CORROSION . z A/C Components Controlled or Activated by Other Control Modules, Electrical Tests, refer to A/C COMPONENTS CONTROLLED BY OTHER CONTROL MODULES, ELECTRICAL TEST . z Components Actuated by A/C System, Electrical Test, refer to COMPONENTS CONTROLLED BY A/C SYSTEM, ELECTRICAL TEST . COOLANT CIRCUIT, SERVICING switches are unscrewed. These switches can thus be replaced in any Audi workshop even though the refrigerant circuit is fully charged. NOTE: No refrigerant must be added into the refrigerant circuit (discharge, evacuate and recharge refrigerant circuit). Refer to General Information . Compressor is always driven when engine is running; there is no magnetic clutch. Engine is therefore not to be started unless refrigerant circuit has been properly assembled. For example; if the refrigerant lines are not connected to A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged. Such internal heat generation results from the fact that - even with delivery near 0% - the compressor is confronted with a fixed resistance (sealed circuit). To stop the A/C compressor from being destroyed when the refrigerant circuit is empty, it is designed such that delivery is reduced to roughly 0% and lubrication is maintained by way of an internal oil circuit with the oil left in the A/C compressor. The entire amount of refrigerant oil to be added to the refrigerant circuit is in the replacement compressor. Refer to Removal and Installation . Different refrigerant oils are required for A/C compressors made by Denso, Sanden and Zexel/Valeo. Refer to Specifications Coat the O-ring with refrigerant oil before installing. Refer to REFRIGERANT CIRCUIT O - RINGS . The specified diameters for O-rings and the tightening torque pertain also to the threaded connections of the refrigerant lines or refrigerant hoses between the separate components. 2012 Audi S4 HVAC Air Conditioning (Sedan)

HD = High-pressure end ND = Low-pressure end Only install O-rings that have been approved to be used with refrigerant R134a. Refer to REFRIGERANT CIRCUIT O - RINGS , General Information Check cooling performance, refer to A/C UNIT, CHECKING COOLING OUTPUT . Check pressures in refrigerant circuit. Refer to Diagnosis and Testing . All refrigerant circuit servicing and test procedures not described in this repair information. Refer to Diagnosis and Testing . Operate the A/C system after filling the refrigerant circuit according to A/C SYSTEM, OPERATING AFTER FILLING REFRIGERANT CIRCUIT . 2012 Audi S4 HVAC Air Conditioning (Sedan)

Fig. 1: Identifying Coolant Circuit, Servicing Courtesy of AUDI OF AMERICA, LLC 1. A/C Compressor Regulator Valve -N280- z Do not remove. z Check activation and function, refer to A/C COMPRESSOR REGULATOR VALVE N280, CHECKING SWITCH - ON SIGNAL . NOTE: The A/C compressor regulator valve is actuated by the Climatronic Control Module -J255- via the Vehicle Electrical System Control Module -J519-. The A/C compressor regulator valve controls the pressure on the refrigerant circuit low pressure side. Check using Vehicle Diagnosis, Testing and Information System VAS 5051 under 2012 Audi S4 HVAC Air Conditioning (Sedan)

2. A/C Compressor z A/C compressor, 4 cylinder, removing and installing, refer to A/C COMPRESSOR ON BRACKET . z A/C compressor refrigerant line, disconnecting and reconnecting, refer to REFRIGERANT LINES, DISCONNECTING FROM COMPRESSOR (4 cylinder) or REFRIGERANT LINES, DISCONNECTING FROM COMPRESSOR (6 cylinder) or REFRIGERANT LINES, DISCONNECTING FROM COMPRESSOR (8 cylinder). z Remove ribbed belt. Refer to [For transmission(s) 0AW] [For engine(s) CALA] Removal and Installation or to [For engine(s) CAEB] Removal and Installation or to [For engine(s) CCBA] Removal and Installation . z A/C compressor, removing and installing, refer to A/C COMPRESSOR . z If a new compressor has been installed or new refrigerant oil has been put into the A/C compressor "Guided Fault Finding". NOTE: When installing the refrigerant pipes and mounts, make sure there is enough space between the belt, the bracket, the belt pulley and the refrigerant pipes. To protect the A/C compressor, the engine should only be started with the refrigerant circuit completely assembled. NOTE: On vehicles with a 6 cylinder 8 cylinder FSI engine the A/C compressor can be removed from the bracket only when the refrigerant circuit has been evacuated. Refer to A/C COMPRESSOR . At start of production, A/C compressors manufactured by Denso (type 6 SEU 14) are being installed on 4 and 6 cylinder vehicles and A/C compressors type 7 SEU 17 are being installed on 8 cylinder FSI vehicles. Compressors from other manufacturers may also be installed at a later time. and Removal and Installation . These A/C compressors are available as replacement parts with different oil fill capacities, therefore note capacity on A/C compressor and the exact part number.Removal and Installation . Depending on compressor type, different refrigerant oil fill capacities may be designated for the refrigerant circuit. The reason for the different oil capacities in the A/C compressor for an otherwise identical refrigerant circuit lies in the design of the compressor itself, note these oil capacities. Too much oil in the circuit leads to high pressures and to a reduction in the system cooling performance, too little oil may lead to lubrication problems in the A/C compressor. Refer to Specifications . 2012 Audi S4 HVAC Air Conditioning (Sedan)

(e.g. after blowing through the A/C system), the A/C compressor must be turned by hand approximately 10 turns. This ensures that the compressor is not damaged when activated. 3. A/C Compressor Belt Pulley /Drive Unit z Replace the A/C compressor belt pulley (4- and 6 cylinder vehicles), refer to BELT PULLEY . z Ribbed belt, removing and installing (vehicles with 4 and 6 cylinder engine). Refer to [For transmission(s) 0AW] [For engine(s) CALA] Removal and Installation or to [For engine(s) CAEB] Removal and Installation or to [For engine(s) CCBA] Removal and Installation . z Ribbed belt allocation (vehicles with 4 and 6 cylinder engine). z For replacing the A/C compressor drive unit (8 cylinder vehicles), refer to A/C COMPRESSOR DRIVE UNIT and COMPRESSOR . 4. Oil Drain Plug z Denso A/C compressors have sealing ring installed, always replace. z Denso compressor tightening torque 30 Nm. z May only be removed to drain refrigerant oil with A/C compressor removed, (rotate the A/C compressor via belt pulley to accelerate refrigerant oil flowing out). Refer to Removal and Installation . 5. Pressure Relief Valve z Do not remove. z Tightening specification for the Denso A/C compressor: 10 Nm. z With O-ring Denso A/C compressor 8.5 mm x 1.75 mm, refer to REFRIGERANT CIRCUIT O - RINGS . 6. Connection With Valve z For removing and installing the valve set when the refrigerant circuit is evacuated, for example, use an adapter from the socket for A/C valves T10364. NOTE: There is an overload protection installed between the belt pulley/drive unit and the A/C compressor input shaft to protect the belt should the A/C compressor get blocked or be difficult to move. If the A/C compressor is runs with resistance, the overload safeguard interrupts the supply of power to it. Rubber elements are installed between belt pulley/drive unit and compressor driveshaft, vibrations which may occur during compressor operation may be dissipated via these rubber elements (damper function at torque fluctuations). Different versions of the pulley are installed depending on the type of A/C compressor and engine, refer to BELT PULLEY . WARNING: The valve insert may be removed only when the refrigerant circuit is empty. 2012 Audi S4 HVAC Air Conditioning (Sedan)

7. A/C Pressure/Temperature Sensor -G395- z Housing color: gray. z Removing and installing, refer to A/C PRESSURE/TEMPERATURE SENSOR G395 . z Checking the signal using Vehicle diagnosis, testing and information system VAS 5051/ in the "Guided Fault Finding" function. 8. Condenser z Refrigerant lines, disconnecting and reconnecting, refer to REFRIGERANT LINES, DISCONNECTING FROM CONDENSER . z Condenser, removing and installing, refer to CONDENSER . z Different versions, . 9. Fluid Reservoir z Fluid reservoir is mounted directly on the condenser. z Removing and installing, refer to FLUID RESERVOIR . z Different versions, z Dryer cartridge (on a condenser with an integrated fluid reservoir), removing and installing, refer to DRYER CARTRIDGE . 10. Refrigerant Line Quick-Release Coupling - High Pressure Side z Disconnecting and connect the refrigerant lines from the quick-release coupling connectors, refer to REFRIGERANT LINES DISCONNECTING FROM QUICK - RELEASE COUPLINGS . z Replace the quick-release coupling completely with the O-ring and support ring, refer to NOTE: The A/C pressure/temperature sensor exchanges information via the Data bus LIN bus with the Vehicle Electrical System Control Module - J519-, then the vehicle electrical system control module transmits the data via the data bus to the Climatronic Control Module -J255-. A High Pressure Sensor -G65- cannot be installed on this vehicle (it only delivers square-wave signals). The temperature measured by the A/C pressure/temperature sensor differs from the actual refrigerant temperature in the refrigerant circuit because of the A/C pressure/temperature sensor design and its component location. Because of this, it is not currently evaluated and is not used to regulate the A/C system. NOTE: The reservoir may be attached to or integrated in the condenser, depending on the version of the condenser. Refer to FLUID RESERVOIR and DRYER CARTRIDGE . WARNING: The quick-release coupling connectors may be unlocked and opened only if the refrigerant circuit is empty. 2012 Audi S4 HVAC Air Conditioning (Sedan)

2012 AUDI S4 B8 Service and Repair Manual

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