Component description for the crankshaft Hall sensor - GF07.04-P-6221CY

ENGINE 272.911 in MODEL 204.0 up to Model Year 8

ENGINE 272.921 in MODEL 204.0 /2 up to Model Year 8

ENGINE 272.947 in MODEL 204.0 /2 up to Model Year 8

ENGINE 272.948 in MODEL 204.0 up to Model Year 8

ENGINE 272.961 in MODEL 204.0 /2 up to Model Year 8

ENGINE 272.971 in MODEL 204.0 up to Model Year 8

Location

The Hall sensor is located behind the left cylinder bank on the transmission flange.

Fig 1: Identifying Crankshaft Hall Sensor With Connector Terminals

Courtesy of MERCEDES-BENZ USA

Task

The Hall sensor detects the position and rotational speed of the crankshaft in a non-contact manner via the increment wheel (perforated plate) on the starter ring gear.

Design

The Hall sensor and its electronics are cast in a plastic housing with a 3-pin connector. The distance to the increment wheel is dictated by the installation position and is about 0.3 to 1.3 mm.

Function

The Hall sensor scans the perforated plate with its 58 links and the gap of 2 links (60-2).

Each 4 mm wide link generates a signal change at the Hall sensor. In the center of the link, the signal changes from approx. 5 V (high) to approx. 0 V (low). No signal change takes place at the gap with the 2 missing links. At the second falling (negative) signal edge after the gap the ME-SFI [ME] control unit (N3/10) detects the top dead center position of cylinder 1.

Fig 2: Identifying Crankshaft Hall Sensor And Increment Wheel (Perforated Plate)

Courtesy of MERCEDES-BENZ USA

Only the negative signal edge of the signal is permanently evaluated. For a frequency measurement, the gap between two negative edges must be measured.

The signal for the rising (positive) signal edge fluctuates and is therefore not used.