Control Unit Function (Coding/Programming), Air-Conditioning System
Control Unit Function (Coding/Programming), Air-Conditioning System
Required status of recirculation valve
- For 2-zone and 4-zone air conditioning systems only.
In the menu item Actual values, the current required position of the recirculation valve can be read out. Numbers from 0 to 8 are output. The meaning of each number is shown below.
0 100% position Fresh air
1 0% position Recirculation air set by air quality sensor
2 0% position Recirculation air set by recirculation button
3 0% position Recirculation air set by wipe and wash signal
4 0% position Recirculation air set by Pull down mode (at high outside temperatures)
5 Intermediate position Partial recirculation air
6 0% position Recirculation set by reverse gear (up to two minutes after engine start)
7 0% position Recirculation air set by air conditioning system regulator at OFF
8 0% position Recirculation air set by blower position 0
Compressor OFF code
In menu item Inputs signals, the actual reason for compressor shutdown can be read out. Numbers from 1 to 19 are output. The meaning of each number is shown below.
NOTE: If the compressor is switched on, the text Comp. ON appears instead of a number.
1. Refrigerant pressure too high
- above 32 bar compressor OFF
- below 26 bar compressor ON again
2. Blower at step 0 (actual voltage less than 3 V) or blower/blower drive circuit faulty
3. Refrigerant pressure too low
- If outside temperature above 5 degree C:
- below +1.4 bar compressor OFF
- above +2.0 bar compressor ON again
- If outside temperature below 5 degree C:
- below +0.5 bar compressor OFF
- above +1.0 bar compressor ON again
5. Engine runs for less than 5 seconds after starting
6. ECON mode active
7. Air-conditioning system OFF
8. Outside temperature too low
- below +2 degree C compressor OFF
- above +3.5 degree C compressor ON again
10. Vehicle voltage too low (less than 10.1 V when engine running)
12. Shutdown request from engine control module via CAN
13. Vehicle voltage too high (greater than 16 V)
14. Evaporator temperature too low
- below -2 degree C compressor OFF
- above 0 degree C compressor ON again
16. Fault A/C compressor drive circuit
17. Fault Pressure sensor
18. Engine speed too high (greater than 3000 rpm when vehicle stationary (0(h))
19. Shutdown request from vehicle electrical system control unit via CAN
Drive links
In menu item Drive links, both a self test (system check) and a test of individual drive links can be performed.
NOTE:
- The vehicle engine must not be running.
- The air conditioning system regulator(s) must not be OFF.
- The engine coolant should be at operating temperature.
- The waiting time until a particular position is set is approx. 5 seconds. Only then can the next step take place.
- Manual, 2-zone and 4-zone air conditioning systems.
- For the self test, the blower(s) is/are first set at 1/2 power. All valves are then driven to the CLOSED position. The blower(s) is/are then set at full power. Finally, all valves are driven to the OPEN position. The procedure lasts about 20 seconds.
- After the self test the individual front valves are checked.
- For checking the individual valves, the front blower is set at 3/4 power.
- The valve under test is driven to the OPEN and CLOSED stops with a 5-second cycle time.
- All other valves are driven to the CLOSED position.
- Only the passenger blower valve corresponding to the front temperature valves is driven to the OPEN stop.
- After activating the front valves, the front blower regulator is set to steps 1/4, 1/2, full and zero power.
- For this procedure, the front passenger blower valve is driven to the OPEN stop, all other valves being driven to the CLOSED stop.
- After activating the front blower regulator, the coolant pump is activated.
- For 4-zone air conditioning system only.
- After the coolant pump, the individual valves at the rear are checked.
- For checking the individual valves, the rear blower is set at 3/4 power.
- The valve under test is driven to the OPEN and CLOSED stops with a 5-second cycle time.
- All other valves are driven to the CLOSED position.
- Only the air flow valve corresponding to the rear temperature valves is driven to the OPEN stop.
- For all valves except the two B-pillar valves themselves, the respective B-pillar valve is driven to the B-pillar stop.
- After activating the rear valves, the rear blower regulator is set to steps 1/4, 1/2, full and zero power.
- For this procedure, the air-flow valve and the right B-pillar valve are driven to the OPEN stop, all other valves being driven to the CLOSED stop.
- Before and after the drive link test, the fault memory must be evaluated:
1. Using the Porsche System Tester II 9588, select the menu item Drive links.
2. Then switch on the air-conditioning system(s) and press the >> key.
- The drive link check can be aborted at any time with the << button.
- Checking of individual drive links can be terminated at any time with the F8 Stop button.
3. Press F8 Start to begin the drive link check.
4. Press F8 Start once more to perform the self test of the air-conditioning system regulator.
- The procedure lasts about 20 seconds and ends automatically.
- All subsequent drive link activations must be terminated with the F8 Stop button.
5. Press the F8 Start button again to activate the next drive link of the air-conditioning system regulator.
6. When the drive link test has run fully through, press the F8 Start button to repeat it or the << button to end.
Coding
In menu point Coding, either heat-absorbing glazing or standard glazing can be coded to suit the vehicle.
NOTE:
- The vehicle engine must not be running.
- The air conditioning system regulator(s) must not be OFF.
Calibration
In menu point Calibration, the end stops of all valves can be taught.
NOTE:
- The vehicle engine must not be running.
- The air conditioning system regulator(s) must not be OFF.
Servicing position
In the menu point Service position, the valves can be driven to a defined position for repair.
NOTE:
- The vehicle engine must not be running.
- The air conditioning system regulator(s) must not be OFF.