Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine oil monitoring, function - GF00.20-P-2009P
Model 203 with ENGINE 271 as of 1.6.05, 272, 642
The oil level check switch (S43) constantly monitors the engine oil level.
The engine oil level cannot be displayed upon driver request with the aid of the multifunction steering wheel (MFL) in the multifunction display (A1p13).
An engine oil level warning message "Check engine oil when during refueling stop" is displayed with "circuit 15 ON", "circuit 61 OFF" and one of the following conditions:
- Engine oil level has reached "Minimum".
- Oil level check switch (S43) is defective.
- Connection to oil level check switch (S43) interrupted.
In order to perform the diagnosis, the motor electronics control unit (N3/10) or the CDI control unit (N3/9) have to be read out via STAR DIAGNOSIS.
The instrument cluster (A1) receives the sensor data over the Controller Area Network bus Class C (engine compartment) (CAN-C) from the vehicle-specific engine control unit.
Oil change
Following each oil change, the Active Service System (ASSYST) must be reset. On resetting, the remaining distance and the remaining time are reset. Resetting can be carried out via the instrument cluster (A1) or via STAR DIAGNOSIS.
On resetting, the following data are stored:
- Current kilometer reading, rounded to 100 km
- Remaining distance
- Remaining time
- Product of quality factors
- In 5 data records the data of the most recent 5 resets
These data can only be read out via STAR DIAGNOSIS.
The starting distance (internal mileage) is reduced if the prescribed quantity of oil is not filled in when the oil is changed.
| Oil level check switch, component description | Engines 271.940/941/946/948 | GF18.40-P-4114KE | |
| Engine 271.942 | GF18.40-P-4112D | ||
| Engine 272.910/920/940/941/960/970 | GF18.40-P-4114V | ||
| Engine 642 | GF18.40-P-4114P |
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.