It consists of a resistor between PP and PE. This resistance is in the connector of the cable and is read out by the car and the charging station. With the help of the PP contact it is recognized how much current the cable can handle. This prevents you from drawing full power from a 32 A charging station, for example, even though the cable can only handle 20 A.
|Resistor||conductor cross-section||max. current|
|1500 Ω (1000 - 2200 Ω)||1,5 mm²||13 A|
|680 Ω (330 - 1000 Ω)||2,5 mm²||20 A|
|220 Ω (150 - 330 Ω)||6 mm²||32 A|
|100 Ω (75 - 150 Ω)||16 mm²||63 A|
From experience, I can add that there are some charging cables that are coded "16 A". They don't work at some charging stations. Type 2 charging stations expect at least a 20 A cable. If the cross-section is correct and the plug allows it, it makes sense to replace the resistor with a 20 A resistor.