gf1840d2000h

Component description of oil sensor

Type gf · topic 18.40 · version 0102 · 2009-05-04

Applies to: ENGINE 642.896 /898 /992 /993 in MODEL 906 ENGINE 646.984 /985 /986 /989 in MODEL 906 ENGINE 651.955 /956 /957 in MODEL 906

Where it sits

Function group 1 Engine › 18 Engine lubrication, engine oil cooling › 18.40 Oil level/oil pressure sensor — Series 646 (models 984, 985, 986, 989) · Series 651 (models 955, 956, 957) · Series 906

Also applies to engines/gearboxes: 642 896, 642 898, 642 992, 642 993

GF18.40-D-2000H

Component description of oil sensor

22.4.09

ENGINE 642.896 /898 /992 /993 in MODEL 906

ENGINE 646.984 /985 /986 /989 in MODEL 906

ENGINE 651.955 /956 /957 in MODEL 906

Component description of oil sensor

D18.40-1109-06

Location

Shown with engine 642

B40 Engine oil sensor

Component description of oil sensor

D18.40-1102-08

Shown with engine 646

B40/5 Engine oil sensor

Component description of oil sensor

D01.45-1127-05

Shown with engine 651

B40/6 Engine oil level sensor

The engine oil sensor or the engine oil level sensor with integrated engine oil temperature sensor (B40/9), with engine 651, is located on the oil pan.

Task

To warn the driver through a display in the instrument cluster (A1) that the oil level is too high or too low.

Detecting the oil temperature.

To detect the oil quality for an oil change interval display according to demand.

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Function

An engine oil sensor or engine oil level sensor with integrated engine oil temperature sensor installed in the oil pan enable the oil level, oil temperature and oil quality to be recorded. The sensor operates in accordance with the capacitive measuring principle and features integrated electronics which analyze the three signals. Information is constantly provided through a pulse width modulation (PWM) signal to one of the following engine control units:

- CDI control unit (N3/20), with engine 642

- CDI control unit (N3/21), with engine 646

- CDI control unit (N3/28), with engine 651

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The CDI control unit sends the corresponding information as messages "T_OIL (oil temperature)", "OIL_LE (oil level)" and "OIL_QUAL (oil quality)" through the Controller Area Network bus Class C (engine compartment) (CAN-C) to the instrument cluster.

Each information block consists of three successive square-wave signals, This is followed by a short pause.

A measured variable is assigned to each square-wave signal. Establishment of the size in each case is based on the duty cycle of approx. 20 to 80%.

The oil quality is measured 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; the precision of the measurement about 3 mm. oil level and oil quality (capacitance of the engine oil) are dependent on each other. The information is first calculated in the CDI control unit before being transmitted via the CAN-C. Fault on engine oil sensor or engine oil level sensor with integrated engine oil temperature sensor are detected by the CDI control unit and entered into the fault memory. The power supply (approx. 5 V) for the engine oil sensor or engine oil level sensor with integrated engine oil temperature sensor is provided by the CDI control unit.