GF67.29-P-2000GI Switching On, Function

GF67.29-P-2000GI Switching On, Function
- as of 1.12.99

Component Identification:

Function sequence
The rear window defroster can be switched on under the following conditions:
- Circuit 61 ON (engine operation recognition)
- Voltage not too low

The presence of c. 61 is connected to the engine compartment CAN bus as c. 61e information by the instrument cluster (A1) and read out by the extended activity module (EAM) (N10/1). C. 61e ensures the presence of minimum engine speed and connection of the charge voltage. Thereby c. 61e is a reliable criterion for recognizing when the engine is operating.

The rear window defroster switch (S21e9) is read in directly and evaluated by the extended activity module (EAM) (N10/1). When switching on, ground is connected to the input of N10/1 for a short time. N10/1 then connects ground to the rear window defroster indicator lamp (S21e2) and to the coil in the rear window defroster relay (F1k1).

The rear window defroster indicator lamp (S21e2) and the rear window defroster relay (F1k1) are actuated via separate lines by the extended activity module (EAM) (N10/1).

The rear window defroster relay (F1k1) connects circuit 30 to the antenna splitter (A2/5). The antenna splitter (A2/5) then supplies the rear window defroster (R1) with electric heating current.

The extended activity module (EAM) (N10/1) also detects when the voltage is too low.