85
Oil level
The oil level in mm can be calculated from the
cooling-down period during the cooling-down
phase by means of a sensor equation. Accu-
racy is approx.
±
3 mm.
Long cooling-down period = oil level too low
(1,000 ms)
Short cooling-down period = oil level too high
(100 ms)
Signal waveform and evaluation
The electronically controlled measuring ele-
ment is heated up slightly for a short period of
time as a function of the momentary oil tem-
perature ( output = high) and subsequently
cools down again ( output = low).
This process is repeated continuously.
In this case, the high times are dependent on
the oil temperature and the low times are pro-
portional to oil level.
Oil temperature
The signal for oil temperature is transmitted
during the sensor cooling-down phase.
The influencing criteria for the flexible service
interval indicator are: oil level, oil tempera-
ture, fuel consumption in l/h per cylinder and
distance covered.
High
Low
Cooling-down phase 200 - 1.000 ms
Heating
phase
Oil temperature
evaluation
25 - 85 ms
In the combi-instrument, the condition of the
oil in the vehicle determined by evaluating
these influencing variables, and the upper
limit values in km (max. 30,000 km) and time
(max. 2 years) until the next service are adap-
ted variably.
Oil level sensor
Bonnet contact
Engine control
unit
Odometer
Dash panel
insert
Warning indicator
1. Priority “min“ oil level
2. Priority “min“ oil level as a function
of distance covered
The upper limit values can be set in
units of kilometres and time as fixed
values via the “Adaptation“ function
in the combi-instrument.
The oil level only influences the FSIA
indirectly.
The factor of fuel consumption is
increased when the fuel level is too
low.
