With Code 450, 670A, Except 580, 581A

Front SAM Control Module With Fuse and Relay Module, Task
with code 450, 670a, except 580, 581a

Task
There are two types of input signals for the front SAM:
- Digital signals
- Analog signals

Reading in digital signals:
The signals are read in either shorter or longer intervals depending on how quickly the processor must react to signal changes.
To ensure that the system does not react to short-term interference, the SAM accepts the signal change only if the new value is read in three times in succession.

Reading in analog signals:
The power supply to the switches and sensors depends on the present battery voltage. Before reading in a switch/sensor, the processor first reads the unfiltered battery voltage. If the voltage is within the valid range, the switch can be read in. This voltage is then set in proportion to the switch voltage. To ensure that the system does not react to short-term interference, the SAM accepts changes only if the new value is read in twice in succession. Sensor values are transferred as physical parameters.

Actuating the heater water circulation pump (only for Code 450 and 670a)
The heater water circulation pump is actuated by the front signal acquisition and actuation module (SAM) as requested by the automatic heater pushbutton control moduleThe front SAM reports the status back to the automatic heater pushbutton control module.
The heater water circulation pump is switched on by the automatic heater pushbutton control module when the ignition is switched off by pressing the REST button. (REST)
The heater water circulation pump is switched off by the automatic heater pushbutton control module after t =30 s and after t = 5 s.

Measuring the outside temperature
The outside temperature sensor measures the temperature outside the vehicle and passes this value to the SAM.
The front SAM then puts this value on the CAN BUS where it can be read in by the automatic heater pushbutton control module and used to control the automatic heater.