Component description of the oil level check switch - GF18.40-P-4114AMG (ML63 AMG)

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ENGINE 156.980 in MODEL 164, 251

ENGINE 156.982 in MODEL 209

ENGINE 156.983 in MODEL 211, 219

ENGINE 156.984 in MODEL 216, 221

Location for an engine with front sump

(Engine 156.980 in model 164, 251)

The oil level check switch is located at the right front in the oil pan top section.

The connector for the oil level check switch is located at the right front on the oil pan top section.

Fig 1: Identifying Oil Level Check Switch Location For Engine With Front Sump

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Location for engine with rear sump

(engine 156.982/83/84 in model 209, 211, 216, 219, 221)

The oil level check switch is located at the rear front in the oil pan top section.

The connector for the oil level check switch is located at the rear front below the oil pan top section.

Fig 2: Identifying Oil Level Check Switch Location For Engine With Rear Sump

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Task

The oil level check switch recognizes the minimum oil level in the engine oil pan and reports going below the minimum oil level to the ME-SFI [ME] control unit (N3/10).

Body (shown with sufficient engine oil level)

Fig 3: Sectional View Of Oil Level Check Switch - Body (Shown With Sufficient Engine Oil Level)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

The engine oil from the engine oil pan reaches the oil level switch via 2 bore holes in the switch housing. The float is moved according to the oil level. The dry-reed contact is closed for an adequate engine oil level by the magnetic field from ring magnets. If the engine oil level becomes too low the dry-reed contact opens and the connection to the ground contact is interrupted. This recognized by the ME-SFI [ME] control unit and a suitable warning signal is sent via the CAN data bus to the instrument cluster (A1).

Short-term fluctuations in level are compensated for by to the size of the oil volume and the 2 bores in the switch housing (e.g. during braking or for cornering) which avoids unnecessary warning signals.