Engine oil information function - GF07.61-P-3026A

ENGINE 111.951 /955 /956 /957 /982 

ENGINE 112.910 /911 /912 /913 /914 /916 /917 /920 /921 /922 /923 /940 /941 /942 /943 /944 /946 /947 /949 /953 /954 /955 /970 /972 /973 /975 

ENGINE 113.940 /941 /942 /943 /948 /960 /961 /963 /965 /966 /967 /968 /969 

ENGINE 137.970 

Shown on ENGINE 112 

Signal assignment oil sensor 

Task 

• The display in the instrument cluster warns the driver that the oil level is too low
• Detecting oil temperature
• Detecting oil quality for demand-based oil change interval display

Design/function 

The oil level, oil temperature and oil quality are detected by means of an oil sensor installed in the oil pan. The sensor operates in accordance with the capacitive measuring principle and features integrated electronics which analyze the three signals.

The information is continuously transmitted via a PWM signal to the engine control unit and communicated via the CAN to the instrument cluster. Each information block consists of three successive square-wave signals, followed by a short pause. This is followed by a short pause. A measured variable is assigned to each square-wave signal (A, B, C). The quantizing in each case is based on the on/off ratio of approx. 19 to 81 %.

The oil quality is detected for the demand-based oil change interval display. The oil quality is detected on the basis of the capacitance of the engine oil (dielectric), this being as much as 6 times greater if the oil quality is poor.

The measuring range for the oil level is 80 mm (normal level ±40 mm), accuracy of measurement approx. ±3 mm.

Oil level and oil quality (capacitance of the engine oil) are independent of each other. The information is not compensated until it reaches the engine control unit before being transmitted to the CAN.

Faults at the oil sensor are detected by the engine control unit and entered in the fault memory.

The voltage for the oil sensor (approx. 5 V) is supplied by the engine control unit.

	Motor electronics control unit, location/task/ design/function	Engine 112, 113, 137	GF07.61-P-5000F
		Engine 111 EVO	GF07.61-P-5000GS
	CAN data bus, function	Vehicles with CAN	GF54.00-P-0005F
	Oil sensor, location/task/design/function	Engine 112, 113	GF18.40-P-4111A
		Engine 137	GF18.40-P-4111L