There are two types of TPS sensors, potentiometer (liner resistor) type and switch type.
Usually they can be identified by the shape, square or rectangular shape indicate onto switch type and round shape indicate onto potentiometer type.
Both throttle position sensors can be check with the multimeter, switch type is easy to check turn multimeter on resistor check, place one of the leads to common ground of the switch and another to next terminal which when its close one of the terminal will read around 0.4 ohms of resistance, showing that its in close position and car runs on idle, next it needs to be fully open to read resistance from other terminal and it will show that butterfly fully open and vehicle needs extra fuel as its accelerating. Third position is when its partly open and reads no resistance on both terminals that normal driving position when vehicle traveling on the same speed on highway. So switch type of throttle position sensor is quite simple as it only shows 3 position
s of butterfly, and a bit useless for good fuel economy and emission control.This graph explain 3 positions of throttle position switch.
Next type is a potentiometer type or liner resistor type. It also can be check with multimeter, but it has to be connected to 5 volts power supply. But to find a fault in broken resistor track better to use a oscilloscope equipment. With 5 volts sup
ply voltage, sensor changes its output voltage with position of butterfly (throttle). It can be from almost 0 volts when throttle closed and up to 5 volts when its fully open, giving all the angles and position of butterfly so ECU can get more accurate reading.This graph shows operation range of linear throttle sensor, where reading were taken at different throttle angles.
This sensor is more common to use this days as it gives more accurate reading for ECU.
