GF54.30-P-4001SX Coolant/Washer Fluid Level Voltage Coding, Function

GF54.30-P-4001SX Coolant/washer Fluid Level Voltage Coding, Function

Component Identification:

The coolant level indicator switch and windshield washer fluid level indicator switch are connected in series and are read in by the front SAM control unit with fuse and relay module.

Voltage coding
The switch (s1) and switch (s2) are connected in parallel for voltage coding of the resistor (r1) and the resistor (r2), the values of resistance (r1) and resistor (r2) must differ. These resistors (r1, r2) form, when switches (s1, s2) are open, together with the resistor (r3) of the front SAM control unit with fuse and relay module, a voltage divider which is supplied with constant voltage (u). The voltage (u e) at the input of the Front SAM control unit with fuse and relay module is dependent on the positions of the switch (s ) and switch (s1) and switch (s2) and the values of the resistances (r1, r2, r3). Each of the switch combinations (s1, s2) produces a different voltage value (u e) at the input of the front SAM control unit with fuse and relay module.

Evaluation
The voltage (u e) is applied at the input of the ADC of the front e SAM control unit with fuse and relay module. The ADC converts the analog voltage into a digital value. The processor compares the digitized value with the threshold values stored in a memory and if necessary places the corresponding messages ("Refill washer fluid", "Check coolant level") on the interior CAN.

The messages can be acknowledged with the OK button (S110s6) of the left multifunction steering wheel button group (S110) of the multifunction steering wheel (MFL).

Switch status and messages
The coolant level indicator switch and the windshield washer fluid level indicator switch result in a total of the following 4 switch combination options and the resultant requests in the multifunction display (A1p13):
^ When the coolant level indicator switch is open and the windshield washer fluid level indicator switch is open, there is no message in the multifunction display.
^ When the coolant level indicator switch is open and the windshield washer fluid level indicator switch is closed, a request to replenish the washer fluid appears in the multifunction display.
^ When the coolant level indicator switch is closed and the windshield washer fluid level indicator switch is open, a request to check the coolant level appears in the multifunction display.
^ When the coolant level indicator switch is closed and the Windshield washer fluid level indicator switch is closed, the requests to check the washer fluid and to check the coolant level appear alternately in the multifunction display.