The throttle position sensor is helping to determine the amount of air that rushes into the engine.

The calculated amount of air is the basis for the calculation of the optimal fuel/air mixture.

If there is a problem with the throttle position sensor the engine will run with a bad fuel/air mixture. The bad air/fuel mixture will result in bad engine efficiency and performance. The driver will often experience starting problems, engine stuttering, loss of power and higher fuel consumption.

The cause of failures will mostly be pollution, corrosion or broken cables.

The most reliable method to diagnose a defective throttle position sensor is checking the trouble code and measuring the sensors resistance.