What is the Throttle/Accelerator Pedal Position Sensor all about?
On older vehicle designs, a simple throttle cable connects the accelerator pedal to the engine and controls the amount of fuel delivered to the engine. However, with fuel injected systems, that has changed. Newer engines now use electronics to control the amount of fuel sent to the engine based on accelerator pedal movement. This is the job of the accelerator pedal position sensor. It’s mounted to the gas pedal, and essentially translates the movement of the pedal (speed and position) into voltage, which tells the car’s computer how much fuel to supply for engine acceleration.
Keep in mind:
- It’s impossible to check the operation of the accelerator pedal position sensor visually as it requires a voltmeter and an understanding of the proper voltage output range.
- It’s possible for an accelerator pedal position sensor to operate intermittently.
- A discrepancy in voltage will put the computer into “limp” mode, which provides significantly reduced power to prevent damage.
How it’s done:
- The throttle pedal position sensor is verified that it needs to be replaced. The throttle trim cover is then removed to access the sensor .
- The defective throttle pedal position sensor is disconnected and removed.
- The new throttle pedal position sensor is installed onto the firewall and reconnected.
- The engine is started and the throttle pedal position sensor is tested for operation. The trim panel is then reinstalled.
- The vehicle is road tested to ensure proper operation of the throttle pedal position sensor.
There is no set service or replacement period for your accelerator pedal position sensor. If you suspect a problem with your accelerator pedal position sensor, have one of our expert mechanics diagnose the system.
What common symptoms indicate you may need to replace the Throttle/Accelerator Pedal Position Sensor?
- Lagging or intermittent acceleration
- No acceleration
- Limited power (limp mode)
- No throttle response in Park or Neutral
How important is this service?
Because the accelerator pedal position sensor tells the car’s computer how quickly you’re depressing the accelerator pedal and controls the supply of fuel to the engine, replacement is very important. While your car will continue to operate even if there is a problem with the sensor, it will do so with limited capacity. Our experienced mechanics will use a voltmeter to determine sensor operation and diagnose the problem accurately. Have a faulty accelerator pedal position sensor replaced immediately.