What is the Throttle Position Sensor all about?

For a car to run smoothly, it needs the proper mixture of air and fuel. The amount of air in the engine is controlled by the air intake system. A throttle body is part of the air intake system that helps control the amount of air that gets into the engine. The throttle body has a throttle plate. If the plate is closed, it prevents the air from getting into the engine. When you push the gas pedal, it opens the plate, allowing the air to enter the engine. The amount of air depends on the position of the plate, which is controlled by the gas pedal. The harder you push the gas pedal, the wider the plate will open, and more air will flow to the engine. This means more power and more speed.

The throttle position sensor reports the position of the gas pedal to the computer in your car (Engine Control Unit). The computer then determines the position of the throttle plate. It also calculates the amount of air flow to the engine and the amount of fuel to be injected for the required ratio of air-fuel mixture.

The throttle position sensor also controls the shifting of the gears. If this sensor stops working, the car's computer will not be able to calculate the right amount of fuel to be injected in the system. It may not be able to change the gears. Your car will not get the right amount of power. It may not even start. The Check Engine light may come on.

Keep in mind:

• When the throttle position sensor is repaired or replaced, it will need to have the minimum idle speed reset to factory specs, and the trouble codes will need to be cleared.
• When a new throttle position sensor is placed in your vehicle, it should be checked for software updates.

How it's done:

• Scan the computer system for codes.
• Test the throttle position sensor and related wiring.
• Remove and replace the throttle position sensor if found faulty.
• Clean the carbon from throttle body.
• Re-install throttle body and reset minimum idle speed to factory specs.
• Clear trouble codes and check for proper operation.
• Test drive vehicle.

Our recommendation:

If you notice that the gears are not changing properly, get the throttle position sensor (TPS) inspected. A good mechanic will clean the throttle body during a tune-up. If the Check Engine light is on, get the car inspected as soon as you can.

What common symptoms indicate you may need to replace the Throttle Position Sensor?

• Engine may be stalling or misfiring.
• Poor engine performance.
• Lack of power.
• Transmission (gear) may not be shifting correctly.

How important is this service?

Your vehicle depends on an optimal mixture of air and fuel in order to run optimally. The amount of air that enters the engine is controlled by the air intake system. The faster your engine is moving, the more air it needs, so your air intake system is in tune with your gas pedal. Your throttle position sensor is constantly sending information about your gas pedal to the vehicle’s engine control unit. The computer then chooses the optimal position for the throttle plate, which is the part of the air intake system that lets air into the engine.

When the throttle position sensor malfunctions, the engine control unit has no information about the gas pedal, and the throttle plate is not utilized. As a result, your vehicle will not get the right amount of air into the engine, and your engine will lose power and run very poorly. In some cases, this will keep your vehicle from being able to change gears.