Oil pressure switch
The oil pressure switch is bolted into the engine block beside the oil filter.
If the oil pressure falls to a level that is too low, the oil pressure indicator light lights up in the instrument panel.
Functional descriptionThe oil pressure indicator light lights up if the oil pressure does not exceed a value defined by a spring. This value is approx. 0.2 to 0.5 bar. If the engine is started, the oil pressure opens the earth contact and the oil pressure indicator light goes out. The oil pressure switch is connected to the engine control system across a signal cable. The data interchange is digital.
|1||Oil pressure switch||2||1-pin plug connection|
Structure and inner electrical connection
When the oil pressure switch is not activated, 12 Volts is applied to this signal line to the engine control system. When the switch is activated, 0 Volts is applied.
|1||Oil pressure switch|
|SIG||Signal, oil pressure switch|
Nominal valuesObserve the following target values for the oil pressure switch:
|Voltage range||9 to 16 Volts|
|Minimum switching point||0.2 bar|
|Maximum switching point||0.5 bar|
|Operating point||6 bar|
|Temperature range||-40 °C to 140 °C|
Failure of the component
If the oil pressure switch fails, the following behaviour is to be expected:
- Check Control message without fault code entry with running engine
- fault code entry in the engine control unit without Check Control message after stopping the engine, if engine oil temperature is above 60 °C
- No Check Control message, no fault code entry
Diagnosis of the oil pressure switch runs within 8 seconds after stopping the engine.