Porsche P-80 2005 Manual
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Porsche P-80 2005 Manual

Porsche P-80 2005 Manual

Aftersales training, climate control systems diagnosis & repair
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AfterSales Training
Climate Control Systems Diagnosis & Repair
P-80

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  • Page 1 ® AfterSales Training Climate Control Systems Diagnosis & Repair P-80...
  • Page 2 Important Notice:The contents of this AfterSales Training brochure was originally written by Porsche AG for its rest-of-world English speaking market. The electronic text and graphic files were then imported by Porsche Cars N.A, Inc. and edited for con- tent. Some equipment and technical data listed in this publication may not be applicable for our market. Specifications are sub- ject to change without notice.

  • Page 3: Table Of Contents

    Table of Contents Chapter Description Section Introduction ............. .i Air Conditioning Basics .
  • Page 4 Climate Control Systems Diagnosis & Repair...

  • Page 5: Introduction

    The rules have changed and today’s customer expects A/C to be an included feature. High levels of performance and comfort are expected. All current Porsche models sold in North America have A/C standard, and all US models are equipped with automatic climate control systems.
  • Page 6 (like the glass panels of a greenhouse). The trapping Porsche phased-in the use of R-134a in 1993. Refer to of too much radiant heat energy is suspected to cause page I-21 for more refrigerant information.

  • Page 7: Air Conditioning Basics

    Air Conditioning Basics Subject Page Air Conditioning Overview ...........1.3 Principles of Heat Transfer .
  • Page 8 Air Conditioning Basics Notes: Climate Control Systems Diagnosis & Repair Page 1.2...

  • Page 9: Air Conditioning Overview

    Air Conditioning Basics Air Conditioning Overview Principles of Heat Transfer There are four principles of heat and heat transfer that Air conditioning is the process of moving heat energy from apply to automotive heating, air conditioning and climate one place in the vehicle to another. Doing this raises or control systems: lowers the temperature of the air in the vehicle interior.
  • Page 10 Air Conditioning Basics 1. Heat always flows from hot to cold. 2. Materials absorb or give off large amounts of heat when changing state. Sweating makes us feel cooler. As liquid water on our skin evaporates, it removes body heat. In a similar way, refrig- erant vaporizing (changing from liquid to gas) inside the A/C evaporator absorbs heat from the warmer air around the evaporator.
  • Page 11 Air Conditioning Basics causing it to change state. The temperature of the 3. The pressure of a liquid or gas varies with its material remains the same during the change of state. We temperature and the temperature of a liquid or can raise the temperature a pot of water to the boiling gas varies with its pressure.
  • Page 12 Air Conditioning Basics 4. The boiling point of a liquid varies with its higher altitudes, such as in Denver, the pressure is lower, pressure. and therefore the boiling point is lower. This is why baking or cooking times are longer at high altitudes. The boiling point of a liquid changes with pressure.

  • Page 13: The Refrigeration Cycle

    Air Conditioning Basics The Refrigeration Cycle As we have said, air conditioning is the process of moving heat energy from one place in the vehicle to another. The High and Low Pressure Sections A/C system is a closed system in which the compressor pumps the refrigerant through the circuit over and over The system is divided into high pressure and low pressure whenever the A/C is ON.

  • Page 14: Compressor

    Liquid refrigerant must be kept out of the All Porsche Sports Cars and Cayenne A/C compressors compressor as it can hydraulic lock and damage it. are variable displacement swash plate designs. Fixed...
  • Page 15 Variable Displacement Compressors Variable displacement compressors are more efficient than fixed displacement compressors because they pump Porsche vehicles today use a variable displacement only enough refrigerant to achieve the desired cooling. compressor. Seven axial pistons are arranged Energy is not wasted pumping more refrigerant than is concentrically around the central compressor shaft.

  • Page 16: Pressure Relief Valve

    Pressure Relief Valve system component. Porsche A/C compressors have a spring loaded mechan- ical pressure relief valve. If system pressures get danger- ously high, the valve will open and vent the excess pressure.

  • Page 17: Condenser

    Some system high pressure side. It is located between the Porsche models use two condensers. The condenser is on condenser outlet and evaporator inlet. Condensed liquid the A/C system high side and contains high pressure refrigerant flows into the receiver dryer from the refrigerant.

  • Page 18: Evaporator

    Air Conditioning Basics Evaporator In addition to removing heat, the evaporator also dehumidi- fies the interior air. Cool air cannot hold as much moisture as warm air. As the air is cooled, moisture condenses and collects on the evaporator fins. Dehumidifying the air adds to passenger comfort and also helps to demist the wind- shield in damp weather.

  • Page 19: Thermostatic Expansion Valve

    High pressure liquid refrigerant flows to the expansion valve inlet from the receiver/dryer. Porsche uses the H-Type block expansion valve. This valve works the same way as the old style right-angle valve with external sensing tubes, but is internally compensated within the valve and has no external lines to the evaporator.

  • Page 20: Lines And Hoses

    Air Conditioning Basics Lines and Hoses A/C system components are connected by rigid lines and flexible hoses. This creates the closed loop through which the refrigerant flows. Rigid lines are formed aluminum. The flexible hoses are a reinforced rubber compound with a barrier liner.

  • Page 21: Refrigerants

    Chlorine which is suspected of damaging the ozone layer and contributing to global warming. R-12 is no longer produced in this country, and Porsche discontinued its use in 1993. R-134a (Tetrafluoroethane, trade name SUVA) is the refrig- erant used today. It has similar heat transfer properties like R-12 but it does not contain Chlorine.
  • Page 22 Air Conditioning Basics Notes: Climate Control Systems Diagnosis & Repair Page 1.16...
  • Page 23 911 Carrera (993) Model System Subject Page A/C System Description Refrigerant System Description ..........2.3 Air Distribution System .
  • Page 24 911 Carrera (993) Model System Notes: Climate Control Systems Diagnosis & Repair Page 2.2...

  • Page 25: A/C System Description

    911 Carrera (993) Model System A/C System Description Evaporator The A/C evaporator is located in the air distribution housing. Evaporator removal requires removal and disas- sembly of the air distribution housing. Thermostatic Expansion Valve (TEV) The H-Type block Thermostatic Expansion Valve (TEV) is located at the evaporator inlet in the center of the cowl.
  • Page 26 911 Carrera (993) Model System Regulating Air Temperature The air distribution housing is located in the front, in the more consistent regardless of engine and vehicle speed. cowl area of the vehicle. The housing includes the evapo- The air is heated by the exhaust heat exchangers. This hot rator, left and right blowers, inlets for fresh (outside) air air then flows through left and right hot air ducts in the and heated air, and air control flaps.

  • Page 27: Heating-A/C Control Unit Operation

    911 Carrera (993) Model System Air Control Flaps Defrost Mode Each duct has a temperature mixing flap to regulate the Depressing the defrost button on the Heater-A/C Regulator hot air supply. The temperature mixing flaps are moved by selects the defrost mode. This mode directs most outlet a servo motor controlled by the processor.
  • Page 28 911 Carrera (993) Model System 911 Carrera (993) Sensors and Actuators Climate Control Systems Diagnosis & Repair Page 2.6...

  • Page 29: Sensors & Actuators

    911 Carrera (993) Model System Sensors and Actuators Evaporator Temperature Sensor The evaporator temperature sensor sends a signal to the Sensors Heating-A/C Control Unit for air temperature exiting the evaporator. When the measured temperature is approx. Refrigerant pressure is monitored to prevent A/C system 0-1°...
  • Page 30 911 Carrera (993) Model System Interior Temperature Sensor Actuators The interior temperature sensor sends a signal to the Compressor Clutch Heating-A/C Control Unit for interior temperature. Interior temperature is sensed and compared with the An electromagnetic clutch engages and drives the target temperature requested by the passengers.
  • Page 31 911 Carrera (993) Model System Auxiliary Blower Fresh intake air is fed to the auxiliary blower when the solenoid is energized and the vacuum servo is actuated The auxiliary blower supplies hot air forward through left under these conditions: and right hot air ducts and ensures that the supply of heated air is not totally dependent on the engine cooling •...

  • Page 32: Service And Diagnosis Information

    911 Carrera (993) Model System Auxiliary Blower Series Resistor Service and Diagnosis Information Heating-A/C Control Unit Diagnosis The Heating-A/C Control Unit is located in the instrument panel and has the manual passenger’s controls. Passengers can select the desired temperature, blower speed and air distribution conditions.

  • Page 33: On Board Diagnostics

    911 Carrera (993) Model System Compressor Clutch 911 Carrere (993) On Board Diagnostics When A/C is turned ON, there is a ten second delay before The Heating-A/C Control Unit processor stores fault codes energizing the compressor clutch and condenser fan. when defects are detected.
  • Page 34 911 Carrera (993) Model System Notes: Climate Control Systems Diagnosis & Repair Page 2.12...
  • Page 35 Sports Cars System Subject Page Sports Cars Systems – 911 Carrera (996)/(997) & Boxster (986)/(987) A/C System Description ...........3.3 Refrigerant System Description .
  • Page 36 Sports Cars System Notes: Climate Control Systems Diagnosis & Repair Page 3.2...

  • Page 37: Sports Cars, 911 Carrera (996)/(997) & Boxster (986)/(987)

    Sports Cars System Sports Cars – 911 Carrera (996)/(997) & Boxster General – 911 Carrera/S (997) (986)/(987) A/C System Description In contrast to the previous 911 Carrera (996) model, the The Boxster (986) was introduced in North America in M.Y. 911 Carrera/S (997) features automatic climate control 1997 and the 911 Carrera (996) in M.Y.

  • Page 38: Refrigerant System Description

    Sports Cars System Refrigerant System Description Condensers Two A/C condensers are used on the 911 Carrera Compressor (996)/(997) and Boxster (986)/(987) models. They are mounted in the front of the vehicle on the left and right- hand sides in front of the engine coolant radiators. Each condenser is cooled by the electric cooling fan to ensure sufficient airflow and heat transfer under all driving condi- tions.

  • Page 39: Air Distribution System

    Sports Cars System Evaporator Air Distribution System The A/C evaporator is located in the air distribution The air distribution system controls air volume, housing. Evaporator removal requires removal and disas- temperature and direction within the passenger compart- sembly of the air distribution housing. ment.

  • Page 40: Regulating Air Temperature

    Sports Cars System Recommended air distribution: Regulating Air Temperature The air distribution housing is attached to the bulkhead under the instrument panel. The housing includes the evap- orator, heater core, blower, air control flaps and actuators, ducts and outlets. Fresh air enters the intake duct in front of the windshield. All air entering the air distribution housing first passes through the evaporator where, with A/C ON, the air is cooled more than desired and dehumidified by the cold...
  • Page 41 Sports Cars System After passing through the evaporator, the cooled airflow Fresh Air Mode splits. Some of this air is directed through the hot heater core and is reheated, the rest bypasses. Outlet tempera- Air can be drawn into the air distribution housing from two ture is directly related to the percentage of air directed to sources: outside (fresh) air, and inside (recirculation) air.
  • Page 42 Sports Cars System Particle Filter A/C Control Unit Function – 911 Carrera (996) & Boxster (986) A particle filter is installed in the fresh air inlet on the right side of the cowl. All fresh air passes through this filter. An optional charcoal filter can also be installed.
  • Page 43 Sports Cars System The instrument cluster provides the following information Air Conditioning, Manual Air Conditioning – to the A/C Control Unit: Boxster/S (987) • Ambient temperature (from the sensor at the right front) Functions – This air conditioning system, which enables •...
  • Page 44 Sports Cars System Control Panel (Manual A/C) Air Conditioning - Automatic Climate Control – Standard on the 911 Carrera/S (997) and optional on the Boxster/S (987) Functions – This air conditioning system controls the interior temperature preselected on the control panel completely automatically.
  • Page 45 Sports Cars System Operation (automatic climate control panel) A - Seat Heating on/off The seat heating settings can be adjusted individually for the left (button A) and right (button G) side. Apart from OFF level, two heating levels can be selected. When the appro- priate button is pressed, the air conditioning control unit (control panel) transmits the altered button status (pressed 1x or 2x) to the vehicle electrical system control unit.
  • Page 46 Sports Cars System 2 – Mode of functioning of automatic recirculation M - Manual Fan Adjustment mode At exterior temperatures of >79° F. (26° C), recircula- In addition to automatic control, the fan output can also be tion mode is selected automatically by the program adjusted manually by way of the rocker switches.

  • Page 47: Sensors And Actuators

    Sports Cars System Sensors and Actuators – 911 Carrera (996) & Boxster (986) Through M.Y. 2000 Climate Control Systems Diagnosis & Repair Page 3.13...
  • Page 48 Sports Cars System Sensors and Actuators – Sports Cars M.Y. 2001 - on (Except Boxster/S (987) w/Manual A/C * For 2005 the A/C pressure switch was changed by connecting directly to the A/C controller line inputs and outputs for infinite radiator fan control. Climate Control Systems Diagnosis &...

  • Page 49: Sensors

    Sports Cars System Sensors The second switch is the medium pressure switch. This is a normally-open switch, and the switch contacts will close Refrigerant pressure is monitored to prevent A/C system when refrigerant pressure typically exceeds 16 bar (232 operation when pressures are very low or high. High refrig- psi).
  • Page 50 Sports Cars System Fresh Air Intake Temperature Sensor Interior Temperature Sensor – Sports Cars Up To M.Y. 2004 The fresh air intake temperature sensor supplies a signal for outside temperature to the A/C Control Unit. The The interior temperature sensor sends a signal to the A/C sensor is mounted in the air distribution housing on the Control Unit for interior temperature.

  • Page 51: Actuators

    Sports Cars System Footwell Outlet Temperature Sensor Air Control Flap Position Sensors The footwell outlet temperature sensor sends a signal to the A/C Control Unit for footwell outlet air temperature. The sensor is located on the lower left side of the air distribution housing.
  • Page 52 Sports Cars System Cooling Fans – Sports Cars Up To M.Y. 2004 The front-end control unit controls the cooling fans (right and left) together via a pulse width-modulated (PWM) signal to an output module. The output module evaluates and processes the PWM signal and relays it to the fans. The cooling fans promote airflow through the engine coolant radiators and condensers to improve heat transfer from the refrigerant to ambient air.
  • Page 53 Sports Cars System Air Control Flap Motors housing airstream to prevent overheating of the module. Do not operate the blower with the blower regulator out of the airstream or with the vehicle fresh air inlet blocked. During a cold start, the voltage to the fresh air blower is reduced by 50% to prevent the unpleasant discharge of cold air.

  • Page 54: Service And Diagnosis Information

    Sports Cars System Service and Diagnosis Information Blower Control (Except Boxster/S (987) w/Manual A/C) The A/C Control Unit regulates voltage to the blower when in the automatic mode. The following conditions affect Climate Control Unit Diagnosis blower voltage: When the A/C system is in the automatic mode, the A/C Cold Start –...
  • Page 55 Sports Cars System Evaporator Notes: Moisture condensing on the cold evaporator fins drains out the bottom of the air distribution housing. Be sure that this drain does not become obstructed or plugged. Water coming from outlets at high blower fan speeds can indicate drain blockage.

  • Page 56: On Board Diagnostics

    Sports Cars System On Board Diagnostics Climate Control Unit The A/C Control Unit monitors its own function and also The A/C Control Unit has four connectors in the rear. From various sensors and actuators. If a fault is detected, a M.Y.

  • Page 57: Information Transmitted Via Can Interface, Sports Cars M.y. 2005

    Sports Cars System Information Transmitted via the CAN Interface – • A/C shutdown (e.g. high and low pressure shutdown) Sports Cars M.Y. 2005 - on • Diagnosis • Stationary period since “ignition off” (from instrument The system communicates the following climate cluster) relevant operating and ambient conditions via the •...
  • Page 58 Sports Cars System Notes: Climate Control Systems Diagnosis & Repair Page 3.24...
  • Page 59 Cayenne Model System Subject Page Cayenne A/C Systems ........... . .4.3 Compressors .
  • Page 60 Cayenne Model System Notes: Climate Control Systems Diagnosis & Repair Page 4.2...
  • Page 61 Cayenne Model System Cayenne A/C System Description Compressor, 2-Zone & 4-Zone The Cayenne is equipped with a swash plate (regulated) The Cayenne V6 has a heating system in conjunction with compressor controlled on the low side that is similar in manual air conditioning for climate control of the function and design to a compressor in a sports car.
  • Page 62 Cayenne Model System Refrigeration Circuit, Cayenne (V6) Refrigeration Circuit, 2-Zone Climate Control The following illustration shows the refrigeration circuit of The cold air circulation in the Cayenne is set up so that the the Cayenne with manual air conditioning. compressor and the expansion valve are the classic sepa- rations between upper and lower pressure sides.
  • Page 63 Cayenne Model System Additional Refrigeration Circuit, 4-Zone Climate Notes: Control 1 - Refrigerant lines for the rear evaporator 2 - Line for the heating circulation for the rear heat exchanger Climate Control Systems Diagnosis & Repair Page 4.5...
  • Page 64 Cayenne Model System Pressure Relief Valve Receiver/Dryer The receiver/dryer on Cayenne models is a replaceable cartridge that is integrated into the right side of the condenser. The cartridge can retain 6-12 grams of water and is serviceable. An access cover is on top of the condenser.

  • Page 65: Air Distribution System

    Cayenne Model System Service Connections With the manual and 2-Zone climate control system, the temperature and air volume for the driver and front passenger can be separately adjusted. Outlets are located in the instrument panel, the rear console, and floor vents under the front seats.

  • Page 66: Air Distribution Components

    Cayenne Model System Air Distribution Components Rear Heating and Cooling Unit These components make up the Cayenne air distribution system: • Air Distribution Housing • Evaporator • Heater Core • Blower • Air Control Flaps • Climate Control Unit • Four-zone Components (optional) Cayenne models with the optional 4-Zone system have a rear heating/cooling unit.

  • Page 67: Auxiliary Park Heater

    Cayenne Model System Auxiliary Park Heater An electric circulation pump, non-return valve and 3/2 way- valve can isolate the park heater from engine coolant. The park heater is operated and set from the front control panel of the A/C system. The park heater can operate in any ignition key position.

  • Page 68: Manual A/C Operation

    Cayenne Model System Air Conditioning, Cayenne (V6) Manual A/C Operation All Cayenne Models have air conditioning that operates with the environmentally friendly refrigerant R134a. Manual air conditioning is used on the Cayennne. The structural design of the manual air conditioning is basically the same as the 2-zone air conditioning.
  • Page 69 Cayenne Model System 2-Zone Climate Control, Cayenne S/T 4-Zone Climate Control (Optional) Operation Operation A - Defost Front Windshield A - Defrost Front Windshield B - Defrost Rear Window B - Defrost Rear Window C - Auto Button (Automatic Operation) C - Auto Button (automatic operation), REST Button (motor resid- D - Automatic Circulating Air, Circulating Air ual warmth for vehicles with 4 zone climate control)
  • Page 70 Cayenne Model System Climate Control Unit The standard Cayenne automatic climate control system provides 2-zone control, while a 4-zone with front and rear control is optional. 2-Zone Both temperature and air volume can be independently set left and right. The system will maintain the set temperature as conditions change.
  • Page 71 Cayenne Model System 4-Zone In addition to the front A/C system, an A/C system for the rear passenger area is available as an optional extra on all Cayenne models. This second A/C system operates inde- pendently of the front system. Here again, temperature, air volume (blower) and left / right air distribution (zones) are individually selectable.
  • Page 72 Cayenne Model System 4-Zone Sensors & Actuators, Rear Climate Control Systems Diagnosis & Repair Page 4.14...

  • Page 73: Sensors

    Cayenne Model System Sensors Evaporator Temperature Sensor The evaporator temperature sensor measures air tempera- A/C Pressure Sensor ture after it passes through the evaporator fins. The evap- orator temperature sensor is located right behind the evaporator. The control unit monitors this sensor to prevent condensa- tion on the evaporator fins from freezing and blocking airflow.
  • Page 74 Cayenne Model System Interior Temperature Sensor Air Quality Sensor The interior temperature sensor sends an analog signal to The air quality sensor monitors ambient air pollution and the Climate Control Unit for interior temperature. sends a signal to the Climate Control Unit. The control unit Interior temperature is sensed and compared with the will command the recirculation flap to close if the concen- target temperature requested by the passengers, and...
  • Page 75 Cayenne Model System Solar Sensor Air Control Flap Position Sensors Automatic Climate Control system air control flap motors have feedback position sensors built-in. Each position sensor is a potentiometer which provides an analog signal to the Climate Control Unit for flap position. 2-Zone Sensors There are 7 air control flap position sensors in the 2-Zone Cayenne air distribution housing:...

  • Page 76: Actuators

    Cayenne Model System Actuators Air Control Flap Motors Compressor Solenoid Regulator Valve The seven cylinder variable displacement A/C compressor is controlled by a solenoid regulating valve mounted on the compressor. The regulating valve is duty-cycle controlled by the Climate Control Unit at a frequency of 400 Hz. Changes in heat load cause the Climate Control Unit to vary the duty cycle.

  • Page 77: Service And Diagnosis Information

    Cayenne Model System Service and Diagnosis Information CAN Bus Comfort High and Low Moisture condensing on the cold evaporator fins drains The Climate Control Unit receives information over the out the bottom of the air distribution housing. Be sure that CAN Bus from sensors which are not directly connected to this drain does not become obstructed or plugged.
  • Page 78 Cayenne Model System Notes: Climate Control Systems Diagnosis & Repair Page 4.20...
  • Page 79 A/C Refrigerant System Service & Diagnosis Subject Page A/C Refrigerant System Service ..........5.3 Environmental Impact .
  • Page 80 A/C Refrigerant System Service & Diagnosis Notes: Climate Control Systems Diagnosis & Repair Page 5.2...

  • Page 81: A/C Refrigerant System Service

    A/C Refrigerant System Service & Diagnosis A/C Refrigerant System Service A/C Service Equipment Before 1992, automotive air conditioning services could By law, all automotive repair facilities performing A/C be performed by anyone with a manifold gauge set, cans system services must have approved equipment to of refrigerant and a can tap.
  • Page 82 A/C Refrigerant System Service & Diagnosis Manifold Gauge Set Service Ports on the Vehicle The port under the low side gauge connects the low side The red and blue service hoses mate with the A/C refrig- service hose to the low side service connection on the erant service ports on the vehicle.

  • Page 83: A/C Refrigerant System Service Procedures

    A/C Refrigerant System Service & Diagnosis A/C Refrigerant System Service Procedures Note: Depending on the system you’re running, deep vacuum is The A/C service station recovers and stores the not created during recovery. If a deep vacuum were refrigerant while the system is being repaired. The service achieved, any water in the system would boil at room station must recycle the refrigerant so that it is pure for temperature and be pulled into the refrigerant storage...
  • Page 84 A/C Refrigerant System Service & Diagnosis Evacuation Replacing PAG Oil Evacuation is the process of creating a deep vacuum of Once the system has been evacuated and a deep vacuum around 29 in. Hg. in the empty A/C system. Usually this is exists, inject any required PAG oil.

  • Page 85: A/C System Performance Testing

    A/C Refrigerant System Service & Diagnosis Recharging A/C System Performance Testing A/C systems can be recharged by two methods: An A/C system performance test should be performed before any service to verify a customer complaint of poor • Pumping liquid refrigerant into the system high side with cooling performance.
  • Page 86 A/C Refrigerant System Service & Diagnosis Importance of a Diagnostic Plan Notes: A planned approach to the diagnosis of an A/C system problem can help you to locate problems faster. These steps are typical: • Perform a performance test • Check the DTC memory •...
  • Page 87 A/C Refrigerant System Service & Diagnosis Diagnosing with Pressure Gauges Normal Pressures and Conditions The A/C compressor is a pump that creates high side and Normal A/C pressures will vary with changes in tempera- low side system pressures. The compressor pumps ture and humidity.

  • Page 88: Warnings And Cautions

    When checking for leaks, pay close attention to potential hazards. connections, o-rings and seals. Porsche Repair Information contains a list of safety Electronic leak detectors can detect very small leaks for precautions and warnings. Read and understand these both R-134a and R-12 refrigerants. The detectors emit an warnings and cautions before starting diagnosis or repair audible signal when refrigerant is sensed.

  • Page 89: Service Equipment Safety

    A/C Refrigerant System Service & Diagnosis • R-134a is not normally combustible, but at pressures Service Equipment Safety above ambient and mixed with excess air, it can be flammable. Do not use compressed air to blow out A/C refrigerant components or containers unless all of the refrigerant has been recovered and the component has been completely removed from the refrigerant circuit.

  • Page 90: First Aid

    A/C Refrigerant System Service & Diagnosis First Aid • If refrigerant contacts eyes or mucous membranes, rinse immediately with large quantities of water and seek medical attention. • If refrigerant contacts the skin, remove the wet clothing and rinse immediately with large quantities of water. Seek medical attention if required.

  • Page 91: Bus Communications

    BUS Communications Subject Page CAN Bus Networking ............6.3 Network Architechure .
  • Page 92 BUS Communications Notes: Climate Control Systems Diagnosis & Repair Page 6.2...

  • Page 93: Can Bus Networking

    ECU 1 ECU 2 ECU 3 Porsche uses two CAN systems. High Speed CAN (CAN - (Fuel System) (Climate Control) (Transmission) C) is used for power train control (engine, transmission, ABS, etc.). High Speed CAN transmits and receives data at a baud rate of 500 K bits/second (500 K baud).

  • Page 94: Network Architechure

    (i.e., the DME in earlier Porsches). CAN bus systems in newer Porsche vehicles use a "Multi- Master" architecture. In this design, ALL controllers have equal ability, and all controllers (nodes) can access the bus freely.

  • Page 95: Bus Logic

    BUS Communications High Speed CAN Node n Node 1 (max. 30) CAN High 120 Ω Ω Bus Level CAN Low CAN High CAN Low Bus Logic - High Speed CAN High Speed CAN control units recognize the two bus signal levels: dominant (zero) and recessive (one). As stated previously, a dominant signal occurs whenever the unit sends out a "0"...

  • Page 96: Can - Drive (Can

    BUS Communications Networking: Cayenne CAN - Drive (CAN-C) Cayenne models use the following networking Data transfer rate: 500 K bits/second (500 K baud) systems: Failure mode: A short or open in one bus line will make • CAN - Drive Bus (CAN-C) data transmission limited or impossible.

  • Page 97: Can - Comfort/Convenience (Can

    BUS Communications CAN - Comfort/Convenience (CAN-B) Data transfer rate: 100 K bits/second (100 K baud) Failure mode: Data transmission remains possible with a short or open in one bus line. 1 - Gateway 2 - Steering Column Switch (with electronic unit) 3 - Vehicle Electrical System Control Unit 4 - Passenger Compartment Roof Control Unit 5 - Rear Convenience System Control Unit...

  • Page 98: Can - Infotainment

    BUS Communications CAN - Infotainment Data transfer rate: 100 K bits/second (100 K baud) Failure mode: Data transmission remains possible with a short or open in one bus line. 1 - Gateway 2 - PCM2 3 - Wiper Motor (with integrated control unit) 4 - Auxiliary Heater Control Unit 5 - Compass Control Unit (magnetic field sensor) Climate Control Systems Diagnosis &...

  • Page 99: Can - Internal

    BUS Communications CAN - Internal: 1 - Combination Sensor 2 - PSM Control Unit Climate Control Systems Diagnosis & Repair Page 6.9...

  • Page 100: Cayenne Data Bus Layout

    BUS Communications Cayenne Data Bus Layout MOST (Media Oriented System Transfer) Optical Bus On Cayenne prior to M.Y. 2005, the instrument cluster is the gateway between the CAN - Drive Bus (CAN-C), the Data transfer rate: 21.2 M bits/second (21.2 M baud) CAN - Convenience (CAN-B) and CAN - Infotainment networks.
  • Page 101 BUS Communications S S t t e e e e r r i i n n g g C C o o l l u u m m n n C C o o n n t t r r o o l l U U n n i i t t K K e e s s s s y y C C o o n n t t r r o o l l U U n n i i t t Climate Control Systems Diagnosis &...
  • Page 102 BUS Communications 911 Carrera/S (997) and Boxster/S (987) Data Bus Layout The overview shows the networking of the control units: A - CAN Drive D - K-line B - CAN Comfort E - Gateway controller C - CAN Display 1 - Park Assist control unit 2 - Motronic control unit 3 - Transmission control unit 4 - PSM control unit...
  • Page 103 BUS Communications Climate Control Systems Diagnosis & Repair Page 6.13...
  • Page 104 BUS Communications Climate Control Systems Diagnosis & Repair Page 6.14...

  • Page 105: Conversion Charts

    Conversion Charts Temperature Conversion Metric Conversion Formulas INCH ... . . X 25.4 MM ....X .0394 INCH MILE .
  • Page 106 Conversion Charts Notes: Climate Control Systems Diagnosis & Repair Page 7.2...
  • Page 108 Part Number - PNA P80 001...

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