What is the detection method for the throttle position sensor?
2 Answers
There are three types of throttle position sensors: switch type, sliding resistor type, and comprehensive type. The detection methods vary for different types: 1. For the switch type, you can use a multimeter to measure the conduction of the idle and full-load switches on the sensor socket. 2. The resistance of the sliding resistor type increases with the opening of the throttle. Check the maximum resistance to see if it meets the requirements. 3. The comprehensive type is also detected with a multimeter. It adds an idle switch on the basis of the sliding type. The main function of the throttle position sensor is to detect whether the engine is in idle condition or load condition, whether it is accelerating or decelerating. It is essentially a variable resistor and several switches installed on the throttle body.
I've been repairing cars for over a decade, and dealing with throttle position sensor failures is routine. The testing method is quite simple: First, turn off the engine and unplug the sensor connector, then use a standard multimeter to measure resistance. Set it to the ohm range and rotate the throttle shaft—the resistance should increase smoothly from low to high. If it's inconsistent or doesn't change, it indicates the sensor is stuck or internally worn. Alternatively, connect the multimeter to measure voltage with the ignition in the ON position (without starting the engine). Slowly press the accelerator—the voltage should rise linearly from around 0.5V to 4.5V. Erratic jumps mean it's faulty. You can also use a diagnostic tool to read trouble codes, commonly P0120. Don’t forget to check for oxidation or loose connections in the plug, as corrosion can distort signals. If the sensor fails, symptoms include rough idling, poor acceleration, and soaring fuel consumption—a small issue causing big trouble, so replace it promptly. Regular cleaning to prevent carbon buildup and dust clogging is key to avoiding failures.
