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.
Oil Level Monitoring
General
The following components are used for oil monitoring:
- engine oil level-/engine temperature sensor (7/166)
- Engine Control Module (ECM) (4/46)
- Driver Information Module (DIM) (5/1).
The sensor is used to inform the driver via the Driver Information Module (DIM) that the oil level deviates too much from the correct level.
Detecting the oil level
The sensor integrated electronics calculate the oil level using the measured value from the level sensor, and with compensation for the oil temperature. Hot oil gives greater volume/level.
The level calculation is carried out on stationary vehicles with the engine switched off and on a flat surface. The calculation is based on the oil running back into the sump, which takes different lengths of time depending on the temperature of the oil. Hot oil runs faster.
Signalling deviating oil level
Low oil level
If the control module calculated oil level is below a certain calibrated level the yellow information symbol lights and text regarding a low oil level appears in the Driver Information Module (DIM). If the level is sufficiently low the Engine Control Module (ECM) stores a DTC and the message for oil service is visible in the Driver Information Module (DIM).
HINT: Applies to vehicles with diesel and petrol engines.
High oil level
If the control module oil level exceeds certain calibrated limits the Engine Control Modules (ECM) stores a DTC and the message about oil service is visible in the Driver Information Module (DIM).
HINT: Only applies to vehicles with diesel engine.
Electronic dipstick
The engine does not have a conventional dipstick.
The oil level can be checked by pressing a button in the passenger compartment using the electronic dipstick that is displayed on the Driver Information Module (DIM). The oil level sensor signal, with corresponding temperature compensation is the basis for what is displayed.
HINT: The level display is first available when the Engine Control Module (ECM) considers that the engine has been switched off for sufficiently long that oil has had time to run into the sump.
For further information, see Design and Function, Driver Information Module (DIM) and in the Driver's manual.
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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.
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