Throttle position sensor
Throttle position sensor |
The throttle position sensor in the Motronic system consist of a variable resistor (controlled by the throttle position), which controls the signal level and by that gives the control module information about the present acceleration.
The throttle position is fed with voltage (5 volts) on pin 1 from the control module pin 12.
Pin 2 has its ground connection on the control module pin 30.
Information about the present throttle position goes from pin 3 on the sensor to pin 53 on the control module. The signal voltage varies between approx. 0.7 volts (idling speed) and approx. 4.5 volts (full throttle).
If an open-circuit occurs the CHECK ENGINE lamp (MIL) and the control module start to use a permanently programmed value, corresponding to a throttle valve angle of 31 °, whereby the idling speed rises to over 1500 rpm.
Throttle angle |
The control module sends out a signal on pin 52 with information about the present throttle angle. The information is used by the control module for the automatic transmission.
The signal is a PWM signal at 100 Hz, which measures:
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approx. 1.3 volts at Idling speed
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approx. 2.2 volts at 2500 rpm (without load)
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approx. 12 volts at wide open throttle
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