ENGINES
471.9 in MODEL 963
W47.50>1010>12
Location
B602 Fuel temperature sensor
The fuel temperature sensor (B602) is on the left>hand side of the crankcase, next to the fuel filter module.
Task
The engine management control unit (MCM) (A4) records the fuel temperature via the fuel temperature sensor (B602).
Design
There is an NTC resistor inside the fuel temperature sensor (B602). NTC stands for "Negative Temperature Coefficient", which means that electrical resistance falls as temperature rises.
Function
The fuel at the fuel temperature sensor (B602) influences the temperature measuring element inside the sensor depending on its temperature and thus the size of the electrical resistance. The engine management control unit (MCM) (A4) derives the associated temperature from the electrical resistance.
GF18.40>W>2010H
Oil pressure sensor, description of components
20.7.11
ENGINE 471.9 in MODEL 963
W18.40>1034>06
Location
B604 Oil pressure sensor
The oil pressure sensor (B604) is screwed on below the coolant pump into the crankcase.
Task
The oil pressure sensor (B604) enables the engine management (MCM) control unit (A4) to determine the current engine oil pressure. W18.40>1029>01 Design 1 Sensor element 2 Sensor membrane 3 Hybrid element
B604 Oil pressure sensor
Function
The engine oil pressure operates on the sensor element (1) of the hybrid element (3) and distorts the sensor membrane (2). There are four pressure>dependent resistances (strain measuring resistors) on the sensor membrane (2). Its bridge circuit is supplied with voltage by an electronic analysis system which also serves for signal amplification and signal correction. The electronic analysis system is powered by the engine management (MCM) control unit (A4) with 5 V direct voltage.
The resistors in the sensor membrane (2) are arranged in such a way that on deforming the sensor membrane (2) two resistors are clinched and two resistors elongated.
Contraction and elongation changes the electrical resistance of the resistors which in turn has effects upon the measurement voltage, which is being applied to the electronic analysis system. The electronic analysis system amplifies the measurement voltage, compensating for possible temperature fluctuations or balancing out possible manufacturing tolerances on the resistances and passes on the cleared out measurement voltage to the engine management (MCM) control unit (A4) which uses it to derive the current engine oil pressure.
GF18.40>W>4117H
Component description for engine oil fill level sensor
20.7.11
ENGINE 471.9 in MODEL 963
W18.40>1033>12
Location
B605 Engine oil fill level sensor
The engine oil fill level sensor (B605) is located onto the right side of the engine and screwed into the oil pan from above.
Task
The engine oil fill level sensor (B605) enables the engine management (MCM) control unit (A4) to determine the
instantaneous fill level as well as the engine oil temperature in the oil pan.
Design
Located inside the engine oil fill level sensor (B605) is a series resistor and resistance wire, which are connected in parallel to each other, as well as an NTC resistor, which is connected before them in series. NTC stands for "Negative Temperature
Coefficient", which means that electrical resistance falls as temperature rises.
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The resistance wire is located in the measuring probe.
The engine oil fill level sensor (B605) is installed in such a way that the measuring probe dips fully into the engine oil when the engine oil level is correct.
The NTC resistor is located at the tip of the sensor.
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Function
Determine engine oil level
Engine oil passes via a feed hole into the measuring probe of the engine oil fill level sensor (B605) and thus directly to the resistance wire.
Depending on how far the resistance wire dips into the engine oil the overall resistance at the engine oil fill level sensor (B605) changes and drops with a reducing engine oil level.
After switching on of the ignition, the engine management (MCM) control unit (A4) applies a measurement voltage every 6 s to the engine oil fill level sensor (B605). It checks the electrical overall resistance of the engine oil fill level sensor (B605) and uses it to deduce the current engine oil level in the oil pan.
Measurement of engine oil temperature
The engine oil at the engine oil fill level sensor (B605) influences the temperature measuring element inside the sensor depending on its temperature and therefore the electrical resistance value. The engine management (MCM) control unit (A4) deduces the associated temperature from the electrical resistance.
GF20.00>W>4100H
Component description for exhaust coolant temperature sensor
20.7.11
ENGINE 471.9 in MODEL 963
W07.04>1078>06
Location
B606 Exhaust coolant temperature sensor
The exhaust coolant temperature sensor (B606) is located on the front side of the coolant manifold which is on the right side of engine between the cylinder head and the exhaust gas recirculation cooler.
Task
The coolant outlet temperature sensor (B606) enables the engine management (MCM) control unit (A4) to determine the current coolant temperature at the engine outlet.
Design
There is an NTC resistor inside the exhaust coolant temperature sensor (B606). NTC stands for "Negative Temperature
Coefficient", which means that electrical resistance falls as temperature rises.
Function
The coolant at the exhaust coolant temperature sensor (B606) influences the temperature measuring element inside the sensor depending on its temperature and thus the size of the electrical resistance. The engine management (MCM) control unit (A4) deduces the associated temperature from the electrical resistance.
GF20.00>W>4110H
Component description for intake coolant temperature sensor
20.7.11
ENGINE 471.9 in MODEL 963
W20.00>1052>06
Location
Shown with code (M5Z) Euro VI engine version
B607 Intake coolant temperature sensor
The intake coolant temperature sensor (B607) is located under the coolant pump on the oil/coolant module.
Task
The coolant inlet temperature sensor (B607) enables the engine management (MCM) control unit (A4) to determine the current coolant temperature downstream of the coolant pump.
Design
There is an NTC resistor inside the intake coolant temperature sensor (B607). NTC stands for "Negative Temperature Coefficient", which means that electrical resistance falls as temperature rises.
Function
The coolant at the intake coolant temperature sensor (B607) influences the temperature measuring element inside the sensor depending on its temperature and thus the size of the electrical resistance. The engine management (MCM) control unit (A4) deduces the associated temperature from the electrical resistance.