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P2109 OBD-II Trouble Code: Throttle/Pedal Position Sensor "A" Minimum Stop Performance

Check Engine Light

P2109 code definition

P2019 is a general OBD-II trouble code indicating a fault with the throttle / pedal position sensor “A” minimum stop performance. This code may be seen with other throttle or pedal sensor codes.

What the P2109 code means

The engine control module (ECM) uses the throttle and pedal position sensor inputs to control the throttle actuator motor. The throttle actuator motor is commanded by the ECM to open and close the throttle plate as needed allowing air into the intake.

When a stop performance is detected with the sensor “A” the P2019 code is set. When P2019 is set, it causes the Check Engine Light to be seen on the dashboard and a failsafe mode to be set. The failsafe mode will remain until the fault is resolved or normal operation is found.

What causes the P2109 code?

Many different components can cause the P2109 code:

  • Failed electronic throttle body
  • Throttle actuator control motor failure
  • Pedal or throttle position sensor has failed
  • ECM that is failing or has failed
  • Open or short in the wiring harness
  • Throttle plate can not move

What are the symptoms of the P2109 code?

Common symptoms of the P2109 code are:

  • Check Engine Light triggered
  • Lack of felt power
  • Engine misfire condition
  • Vehicle stalling while running or upon start up
  • Vehicle may have no throttle operation

How does a mechanic diagnose the P2109 code?

A mechanic will begin by checking for all codes stored in the ECM, which means pending codes and history codes as well. These codes, as well as their freeze frame data, will be noted for later use. Now, all the codes will be cleared for a clean slate.

Next, a test drive will be performed under similar conditions as the freeze frame data if possible. Once returning from the test drive, a visual inspection will be done to look for any obvious signs of damage or broken components.

Next, the scan tool will be used to monitor the throttle and pedal sensor readings while the throttle is operated. The technician will then check for voltage at the throttle actuator. If voltage is present, the air intake tube will be removed to check if the throttle plate is capable of operating. Lastly, the ECM will be tested as needed.

Common mistakes when diagnosing the P2109 code

The most common mistake is a failure to perform steps in the proper order or skipping steps completely. When this happens, it can lead to simple things being missed which wastes time and money and can cause good components to be replaced.

How serious is the P2109 code?

The P2109 code can have some rather serious side effects, with the chief of these issues being the vehicle not moving while pressing the throttle. This is due to a failsafe mode that is enabled when the fault is detected and done to protect the vehicle. P2109 should be repaired as soon as possible.

What repairs can fix the P2109 code?

A wide array of repairs can fix the P2109 code:

Additional comments for consideration regarding the P2109 code

An advanced level scan tool is critical for diagnosing the P2019 code. These allow the technicians to view the data stream found in the ECM. The data stream shows live sensor readouts and shows the changes in values over time. This gives information that would otherwise be extremely difficult to obtain.

Need help with a P2109 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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