Diesel diagnostics
Gasoline diagnostics
Car sensors
Complex Engine Diagnostics
CSS script documentation
Px script documentation
ElPower script documentation
Pressure Pulse diagnostics
The vehicle speed sensor is usually installed in the gearbox. The sensor generates a constant number of pulses for each revolution of the vehicle wheel, which allows the engine control unit to calculate the current vehicle speed.
The signal from the vehicle speed sensor is used to control the engine idle mode, and in some models, to display the current vehicle speed on the speedometer.
In case of the vehicle speed sensor breakdown, unstable engine operation at idle while the vehicle is moving is possible, and the engine may stall when shifting gears.
Typical waveform from a Hall effect rotational speed sensor
Zoomed signal
Output voltage waveform from an MR wheel speed sensor. The sensor itself is working properly, but the magnet in the wheel bearing assembly is cracked or broken. Note that these sensors are current mode versus voltage mode sensors. They output a varying current, Usually 7 and 14 mA.
Zoomed waveform from an MR wheel speed sensor
Typical waveform from inductive rotational speed sensor
Zoomed waveform from inductive rotational speed sensor
