"P" stands for programming mode. This allows you to alter machine settings. For example, you can alter the Water Plus button to either give you more water for the rinses, the wash and the rinses, an extra rinse or more water for both washing and rinsing and an extra rinse. In the display, this corresponds to P1 to P4. You can also turn suds-cooling on and off, extends soaking times etc.
The service mode allows you to temporarily test all the parts of the machine (motor, heater, pressure switch etc.) – but it doesn’t change the machine’s programming.
I’d be interested in knowing, how to access more programming options than those indicated in the manual – like the hidden options on the American W4080, which are displayed once you access the hidden service menu:
01 Reset
02 Language (listing)
03 Water Plus Water+, Extra Rinse, Water+/Extra Rinse
04 Gentle Action Off, On
05 Suds Cooling Off, On
06 Temperature Celsius, Fahrenheit
07 Buzzer (scale)
08 Keypad Tone (scale)
09 Display Contrast (scale)
10 Brightness (scale)
11 Standby On, Not in Current Plan
12 Memory Off, On
13 Drum Lighting Off, On
14 Water Intake Cold, Hot + Cold
15 Maximum Water Level Off, On
16 Flow Meter No, Yes
17 Low Water Pressure No, Yes
18 Rinse Process No, Yes
19 Allergy Off, On
20 Country Version (listing)
21 Automatic Load Control Off, On
22 Heater Rating 760W, 1060W, 2100W, 2500W, 2600W, 3000W, 4200W, 4600W, 5300W, 8100W
23 Drum Capacity ASA, NSA
24 Imbalance Charts Chart 1, Chart 2
25 Maximum Spin 1200rpm, 1300rpm, 1400rpm, 1500rpm, 1600rpm, 1700rpm, 1800rpm, 1900rpm, 2000rpm
26 Water Valve Valves, Water Guide (4 pos), Water Guide (5 pos)
27 Machine Front Loader, Top Loader
28 Hygiene Info Off, On
29 Bleach Off, On
30 Exit