Air Conditioning - Introduction
Air conditioningIntroduction
NOTE: The following document was created for manual air-conditioning, automatic 2-zone air-conditioning and automatic 4-zone air-conditioning systems.
Distinguishing characteristics
The various air-conditioning systems can be distinguished from one another via the diagnosis software number in the PST 2 menu option 'Identification' as follows.
- The diagnosis software number 01xx stands for 2-zone air-conditioning.
- The diagnosis software number 02xx stands for 4-zone air-conditioning.
- The diagnosis software number 03xx stands for manual air-conditioning.
The 3rd and 4th characters identify the software version for the corresponding air-conditioning system.
General instructions/safety instructions
CAUTION:
Danger of damage due to improper handling of batteries and control module plug connections.
- Disconnect the battery connection terminals only when the engine is switched off.
- Start the engine only when the battery connection terminals are properly connected.
- Pull off or push on plug connections for the control units or other electronic components only when the ignition is switched off.
- Disconnect the negative terminal of the battery before welding work on the vehicle.
WARNING:
Danger of injury as a result of contact with liquid or gaseous refrigerants.
- Wear suitable protective gloves to protect your hands.
- Treat affected skin in the same way as in the case of freezing. Rinse immediately with cold water and then consult a physician.
- Wear safety goggles to protect your eyes.
- If refrigerant still gets in your eyes, consult a physician immediately.
- When working on the refrigerant circuit, always read the related introductions and warnings.--> 8; Rep. Gr. 87; Safety regulations for working on air-conditioned vehicles and dealing with refrigerant R 134a --> 8; Rep. Gr. 87; Safety regulations for working with extraction and filling systems
WARNING:
Risk of injury.
Do not smoke. Refrigerants could decompose in the burning ash. The resulting substances are toxic and should not be breathed in.
The leaking refrigerant is not only colourless and odorless, but is also heavier than air and therefore displaces oxygen. If refrigerant gas escapes despite all safety measures having been taken, there is an undetectable risk of suffocation in poorly ventilated rooms and erection pits.
The gas/air mixture formed when refrigerant escapes should not be breathed in but rather extracted via suitable extraction systems (workshop extraction system).
No welding, soldering or hard-soldering should be carried out on any part of the filled air-conditioning system. This also applies to welding and soldering work on the vehicle when there is a danger of parts of the air-conditioning system heating up. The warming causes very strong overpressure in the system, which can destroy components of the air-conditioning system.
NOTE:
- Communication with the air-conditioning system regulator control module can only be established once the ignition is switched on.
- The fault memory of the air-conditioning system regulator control module must be read out before troubleshooting.
Troubleshooting procedure
Specific troubleshooting can only be performed in accordance with instructions (given under Diagnosis/troubleshooting for each fault code) if the entry has the status 'present' in the fault memory.
If the fault is currently 'not present', please check the following:
- Diagnostic conditions are met.
- All plug connections and ground points of the affected current path are OK.
- Set all wiring harnesses of the affected current path to a state that corresponds to driving by pulling and shaking them.
Diagnostic conditions
NOTE:
Important: Always connect a suitable battery charging device to the vehicle electrical system battery before starting diagnosis. All unnecessary loads must also be switched off.
NOTE:
The fault can only be identified if the requirements listed under Diagnostic conditions are met. For this reason, the specified procedure must be observed after a fault is repaired:
1. Clear fault memory.
2. Satisfy the requirements listed under 'Diagnostic conditions'.
3. Read out fault memory again
Possible causes of fault
NOTE:
The 'possible causes of fault' that are responsible for the fault are listed here. Please note that in certain circumstances further faults can be stored in the fault memory after troubleshooting (e.g. if plugs are disconnected). After carrying out repairs, read out the fault memory of all control modules and erase any faults.
Diagnosis/troubleshooting
NOTE: The fault memory Info key [F8] on 9588 Porsche System Tester II can be used to access the 'extended fault memory'. The following information can be displayed:
Fault type
The following fault types are possible:
- No display
- Upper limit value exceeded
- Lower limit value not reached
- Mechanical fault
- No signal/communication
- No or incorrect basic setting/adaptation
- Short circuit to B+
- Short circuit to ground
- Implausible signal
- Open circuit/short circuit to ground
- Open circuit/short circuit to B+
- Electrical fault in electric circuit
- Please read out fault memory
- Faulty
Fault status
The following status types are possible:
- present
- not present
This information should be saved using the Save key [F4] and printed out.
NOTE:
Visual inspection: During troubleshooting, please check first that the affected pins on the plug connection of the air-conditioning system regulator control module are neither damaged nor corroded. The wiring and plugs of the affected components must also be checked for external damage and correct contacts. Repair damaged or corroded pins it possible, otherwise replace affected pins. Repair or replace damaged wires.
NOTE:
Battery voltage: A battery voltage of between 11.4 and 14.5 V is required for troubleshooting. This must be checked and provided if necessary. Voltages as well as components or fuses (input side) must be guaranteed on the vehicle electrical system.