When the throttle valve opening angle becomes greater than 72 degrees, the resistance will be equal to 0 Ω. Throttle-Position-Sensor. If the throttle position sensor fails, your ECU doesn't know how much air is passing through the valve. Also there are separate idle and full load switches. Connect ohmmeter between the ground and the full load mode terminals. A Throttle Position Sensor (TPS) usually detects heat, light, and even moisture. What Does a Throttle Position Sensor Do? Using a DMM is the method most DIYers are comfortable with. Regardless of the location of the switch, the verification procedure is performed similarly for all types of sensors.-- Check TS voltage, NOTE: In some cars the throttle valve switch could not be adjusted.-- Check TS resistance, -- Possible damages in TS:      1) Can not get voltage 0V (closed throttle valve), 2) Voltage is low or missing (the throttle valve is opened), 3) The voltage is normal (throttle valve is opened), 4) Voltage is low or missing (the throttle valve is closed or slightly open), 5) The voltage is normal (the throttle valve is closed or slightly open). It does this by monitoring how to open the butterfly valve in your throttle is, which opens more or less depending on how far down you press the gas pedal. Connect an ohmmeter between the potentiometer wiper and the reference voltage terminal or between the potentiometer wiper and the ground. If the voltage does not drop most likely the throttle switch is malfunctioning. You must see a signal as in fig. More advanced forms of the sensor are also used. This throttle position sensor works in tandem with the engine control unit to properly control the engine airflow. How to Test a Throttle Position Sensor. The third wire is connected to the potentiometer wiper, thereby the changing the resistance and hence the voltage of the signal returned to the onboard computer. Check the presence 5.0V voltage in the full load mode contact of the connector. Working Principle Here, this information is used to control the throttle body which forms an integral part of the air intake unit. Some engine control units (ECUs) also control the throttle position electronic throttle control (ETC) or "drive by wire" systems, and if that is done, the position sensor is used in a feedback loop to enable that control.[1]. The magnet may be of diametrical type, ring type, rectangular or segment type. The biggest problem with a TPS is that it’s so small and intricate, that repairing it is almost always out of the question. Garrick, R.D., Sensitivity of Contact Electronic Throttle Control Sensor to Control System Variation, Society of Automotive Engineers (SAE) Technical Paper, 2006-01-0763, April 2006. When you press down on the gas pedal, your throttle body unit's valve opens. Some engine control units (ECUs) also control the throttle position electronic throttle control (ETC) or "drive by wire" systems, and i… The three wires entering the throttle switch coupling are grounding, idle mode signal and full load signal. Connect the positive terminal of a voltmeter to the wire, connected to the idle signal contact of the throttle switch. The Throttle Position (TP) sensor and accelerator pedal position (APP) sensor are the only sensors sending data to the Powertrain Control Module (PCM) that the vehicle operator has direct control over. Turn on the ignition, but do not start the engine. The throttle position sensor (TPS) is an essential part of your vehicle’s fuel management system, tasked with ensuring that a precise blend of air and fuel is routed to your engine. What Is a Throttle Position Sensor? Connect the positive terminal of a voltmeter to the wire, connected to the full load mode switch contact. Modern day sensors are non contact type. A throttle position sensor is similar to the motor cortex in the human brain, it controls one of the most important components of the car that keeps your engine running like a throttle body. The sensor is usually located on the butterfly spindle/shaft, so that it can directly monitor the position of the throttle. TPS is a three wire potentiometer. The sensor signal is used by the engine control unit (ECU) as an input to its control system. Check the condition of the potentiometer grounding contact. 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