S54.18-0015-01
Connector assignment, climate control pushbutton control unit connector A20.2
1 Voltage supply terminal 30 (free on manual heating)
2 Activation of A/C control auxiliary coolant heater pump (free on manual heating)
3 Radiator fan M34 (step 2 switching on, code H06 and diesel engine only)
4 Auxiliary coolant heater operation detection (code H12 only)
5 Cycle valve (Tempmatic only)
6 Coolant pressure sensor voltage supply, air conditioning control (code H06 only)
7 Diagnostic cable (free on manual heating)
8 Voltage supply terminal D+ (manual heating only)
9 Voltage supply terminal 58k
10 Heater booster operation switch-on signal (codes MQ3, MQ4, MQ5, HZ5 or diesel engine with code H12 only)
11 Air circulation valve
12 Activation of air conditioner compressor coupling (code H06 only)
13 Evaporator temperature sensor (code H06 only)
14 Connection to radiator module A50 (code MR9 only)
15 Ground terminal 31
16 Air outlet temperature sensor (free on manual heating)
17 CAN high (free on manual heating)
18 Ground sensor
19 Air conditioning control coolant pressure sensor signal (code H06 only)
20 CAN low (free on manual heating)
21 Voltage supply terminal 15
S83.57-2501-01
Connector assignment, climate control pushbutton control unit connector A20.1
1 Cable step 1
2 Cable step 2
3 Cable step 3
4 Cable step 4
5 Voltage supply terminal 30