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

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

Component Identification:

The coolant level indicator switch (S41) and the windshield washer fluid level indicator switch (S42) are connected in series and are read in by the driver-side SAM control unit with fuse and relay module (N10/1).

Voltage coding
The switch (s1) and switch (s2) are connected in parallel for voltage coding the resistor (r1) and resistor (r2). The values of the resistance (r1) and resistor (r2) must differ. These resistors (r1, r2) form, when the switches (s1, s2) are open, together with the resistor (r3) of the driver-side SAM control unit with fuse and relay module (N10/1) a voltage divider which is supplied with constant voltage (u). The voltage (u e) at the input of the driver-side SAM control unit with fuse and relay module (N10/1) is therefore dependent on the position of the switches (s1, s2) and the values of the resistors (r1, r2, r3). Each switch combination produces another voltage value (u e) at the input of the driver-side SAM control unit with fuse e and relay module (N10/1).

Evaluation
The voltage (u e) is applied at the input of the Analog Digital Converter (ADC) of the driver-side SAM control unit with fuse and relay module (N10/1). The analog-to-digital converter (ADAC) converts the analog voltage into a digital value. The processor compares the digitized values with threshold values stored in a memory and, if necessary, places the signal CHECK COOLANT LEVEL" or "CHECK WASHER FLUID LEVEL" on the Controller Area Network-Bus class B (CAN-B). The instrument cluster (A1) reads these signals and actuates the upper multifunction display (A1p13).

Switch status and messages
Using the coolant level indicator switch (S41) and windshield washer fluid level indicator switch (S42) produces a total of the following 4 switching possibilities and the resultant displays in the upper multifunction display (A1p13):
^ When the "coolant level indicator switch (S41) is OPEN" and the "windshield washer fluid level indicator switch (S42) is OPEN" no message appears in the upper multifunction display (A1p13).
^ When the "coolant level indicator switch (S41) is OPEN" and the "windshield washer fluid level indicator switch (S42) is CLOSED the message "CHECK WASHER FLUID LEVEL" appears in the upper multifunction display (A1p13).
^ When the "coolant level indicator switch (S41) is CLOSED" and the "windshield washer fluid level indicator switch (S42) is OPEN" the message "CHECK COOLANT LEVEL" appears in the upper multifunction display (A1p13).
^ When the "coolant level indicator switch (S41) is CLOSED" and the "windshield washer fluid level indicator switch (S42) is CLOSED" the message "CHECK COOLANT LEVEL" appears in the upper multifunction display (A1p13). The message "CHECK WASHER FLUID LEVEL" has a lower priority and is therefore not displayed directly.