Calculation Of Engine Oil Level; Oil Temperature; Characteristic Curve: Oil Temperature Sensor - Mercedes-Benz M 447 hLAG Service Manual

4.1.16 Calculation of engine oil level

Oil level sensing is currently NOT offered on the M 447 hLAG gas engine and is deactivated. The oil level,
top-up quantity and oil level warnings are set to "Signal not available" (s.n.a. = 102 % or -12.8 l) with the
sensing function switched off.

4.1.17 Oil temperature

The oil temperature is calculated every 40 ms. The calculated temperature is smoothed with a low-pass
filter. The characteristic curve of the oil temperature sensor is stored in the engine data record. If the
voltage of the oil temperature sensor is above 4.97 V or below 0.10 V for more than 2 seconds, then the
event "Fault measuring range exceeded or dropped below" is detected and the fault codes 1015 and
1016 are entered. The substitute value of 85 °C is then used as the oil temperature. If the fault
debouncing time has not yet expired, however the voltage value is outside the limits, the last oil
temperature calculated under valid conditions is retained. In the case of a fault, the measured value on
the CAN is set to "Signal not available".

Characteristic curve: Oil temperature sensor

SEN - T oil: sensor code
Oil temperature [°C] = f(Sensor voltage [V])
Status September 2003 (EvoBus-Service / AFT)
Voltage
Diagnose
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