6 Series E64 650i (N62TU) CONVER
The 2nd Hall sensor always generates exactly half the voltage signal of the 1st Hall sensor. The two signal
voltages are permanently monitored by the DME.
The accelerator pedal module receives a constant voltage of 5 volts from the DME. For safety reasons, each
Hall sensor has its own power supply from the DME.
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Hot-film air-mass sensor with intake air temperature sensor
The hot-film air-mass sensor records the air-mass which is drawn in. The DME control unit calculates the charge
state using this information (base value for fuel injection period).
A heated area on the hot-film air-mass sensor in the intake air flow is regulated to a constant excess
temperature to the intake air. The intake air flow cools the heated area. This causes the resistance to change.
The heater current needed to maintain the excess temperature is the measured variable for the intake air-mass.
The new hot-film air-mass sensor (HFM 6) now works digitally. The electronic evaluation unit in the hot-film air-
mass sensor digitalises the sensor signal.
The hot-film air-mass sensor supplies a pulse-width-modulated signal to the DME.
The integrated supply module provides the power supply to the hot-film air-mass sensor.
> E70
Power supply from front power distributor in junction box
There is also an intake air temperature sensor in the hot-film air-mass sensor housing. The intake air
temperature sensor is a resistance with negative temperature coefficient (NTC).
The intake-air temperature is input into a great many DME functions, e.g.:
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Ignition timing calculation
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Knock control adaptation
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Idle speed control
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VANOS actuation
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Valvetronic actuation
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Electric fan actuation
A fault in the intake air temperature sensor will cause an entry to be stored in the DME fault memory. A
substitute value is then used for engine operation.
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Crankshaft sensor
The crankshaft sensor records the position of the crankshaft with the aid of an increment gear screwed to the
crankshaft. The crankshaft sensor is required in order to achieve fully sequential fuel injection (individual fuel
injection for each cylinder at optimum firing point). The crankshaft sensor works according to the Hall effect.
The circumference of the increment gear is divided into 60 equal teeth. The crankshaft sensor generates signal
pulses. These signal pulses become shorter as the engine speed increases. The precise position of the pistons
must be known for the fuel injection and the ignition to be synchronised. The increment gear has a gap of 2 teeth
for this purpose.
The number of teeth between the two gaps is permanently monitored. The signals from the camshaft sensors
are compared to that from the crankshaft sensor. The signals must be within specified limits.
If the crankshaft sensor fails, a substitute value is generated from the camshaft sensor signal (for engine starting
and running).
The integrated supply module supplies voltage to the crankshaft sensor.
> E70
Power supply from front power distributor in junction box
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Coolant temperature sensor
The coolant temperature sensor records the coolant temperature in the engine cooling circuit.
SBT 8-cylinder spark-ignition engine N62TU E60, E61, E63, E64, E65, E66, E70
BMW AG - TIS
06.02.2013 10:29
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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