Many vehicles have computerized systems that automate the car driving system. These vehicles have a ‘throttle position sensor’ (TPS). This TPS transmits the required information, directing the computer of the car engine. This data is used by the computer of the car to regulate the power of the engine. The TPS basically controls the engine’s power transmission, and then, any fault in this will lead to stumbling of the engine while you try to accelerate it along with other disturbances with the car engine. Checking and adjusting the throttle position sensor of the car is very easy. If you have little knowledge about the mechanics of the car and its electrical circuits, and know how to adjust throttle position sensor, you can resort to troubleshooting methods for your car’s TPS.
For the adjustment of the TPS of a car, you would need two pins and a voltmeter. Besides, keep your car tool-kit handy, and the car’s user manual handy, for reference. You might need it if you have any problem in understanding the parts of the car, and the mechanics or electrical circuits of your car.
How to adjust throttle position sensor?
- When you open the car’s hood, you can see the throttle position sensor (TPS) located in the car’s engine stall. It is located towards the left or right hand side of the plate shaft of the carburetor or throttle body.
- A tiny black colored box having three wires can be seen stemming out from the throttle body’s electrical connector.
- Before switching on the ignition switch of the car, unplug this electrical connector. You need to check the connectors voltage. Use the voltmeter and connect its terminals to this connector to check the voltage.
- The lead marked with negative sign, most likely the black colored wire should connect to the positive end of the voltmeter. The reading on the voltmeter should be around 5.0 volts.
- If the voltmeter fails to show this reading, there is either a short or open in the wire supplying voltage to the connector. Again turn the ignition switch off and plug in the connector in the TPS.
- Now test the voltage signal of the TPS on the computer of the car. The two pins will be used now. Insert one pin in the wire that signals voltage, and another wire in the ground wire. Using the alligator clips, connect the probes of the voltmeter to these pins. After having connected it properly, turn on the engine of the car.
- Close and open the engine’s throttle plate and check the readings of the voltmeter. The voltage reading on the meter should rise from 1-5 and again fall back to 1. If the voltage fluctuates or you hardly see any movement in the voltage, place the TPS back and turn the engine off.
- Next step is testing the resistance of the TPS. If your car’s TPS has been fitted with variable resistor, you can check it using this method. Firstly, unplug the connection of the TPS. The multimeter should be set at ‘ohms’. The probes of the ohmmeter should be connected to the signal wires and supply to the sensor.
- Again follow the same technique of opening and closing the engine’s throttle plate manually, and check the readings on the ohmmeter. As and when this throttle plate closes and opens, the reading of the resistance should rise and fall. Again if you see fluctuations or no resistance, or no change at all, place the TPS back.
- Some sensors of the TPS have to be adjusted on regular intervals. Some mounting screws that control and allow the rotation of the sensors, need to be adjusted. Keeping the ohmmeter connected loosen these mounting screws. Turn the sensor to get the specified resistance for your car. At the point where you get the right reading, tighten the screw. Again check the resistance, using the ohmmeter as mentioned above.
- If the resistance is fine, plug back the connector and turn on the engine. Test-drive your car for smooth acceleration, to check if the TPS is working correctly.
Basically, checking the readings on the voltmeter and ohmmeter will help you understand the condition of your car’s TPS. This is not a difficult procedure because you just need to connect the voltmeter and ohmmeter, and if the readings shown on the meters are not as per the specified guidelines, rotate the sensors till you get the right reading.