P2109 Throttle / Pedal Position Sensor at Minimum Stop

P2109 Throttle / Pedal Position Sensor at Minimum Stop

OBD-II DTC Datasheet

Throttle / Pedal Position Sensor A at Minimum Stop

What does this mean?

This is a generic powertrain diagnostic trouble code (DTC) and is commonly applied to OBD-II vehicles. This may include, but is not limited to, vehicles from Toyota, Subaru, Mazda, Ford, Chrysler, Dodge, Hyundai, Jeep, Kia, Volvo, etc. Although general, exact repair steps may vary by year, make, model and transmissions. configuration.

A stored code P2109 means the powertrain control module (PCM) has detected a malfunction in the throttle position sensor "A" (TPS) or specific pedal position sensor (PPS).

The designation "A" refers to a specific sensor. Consult a reliable vehicle information source for detailed information specific to the vehicle in question. This code is only used in vehicles that are equipped with drive-by-wire (DBW) systems and refers to minimum stop or closed throttle performance.

The PCM controls the DBW system using the throttle actuator motor, multiple pedal position sensors (sometimes called accelerator pedal position sensors), and multiple throttle position sensors. Sensors are usually supplied with a 5V reference, ground and at least one signal wire.

Generally speaking, TPS / PPS sensors are of the potentiometer type. The mechanical extension of the accelerator pedal or throttle shaft actuates the sensor contacts. Sensor resistance changes as the pins move across the sensor PCB, causing changes in circuit resistance and signal input voltage to the PCM.

If the PCM detects a stop / close throttle position sensor minimum voltage signal (from the sensor labeled A) that does not reflect the programmed parameter, code P2109 will be stored and a malfunction indicator lamp (MIL) may illuminate. When this code is stored, the PCM usually enters lame mode. In this mode, engine acceleration can be severely limited (unless disabled completely).

Throttle position sensor (DPZ):

What is the severity of this DTC?

P2109 should be considered serious as it could make it impossible to drive.

What are some of the symptoms of the code?

Symptoms of a P2109 trouble code may include:

• Lack of throttle response
• Limited acceleration or no acceleration
• Engine stalls when idling
• Oscillation on acceleration
• Cruise control is not working

What are some of the common causes for the code?

Reasons for this P2109 Throttle / Pedal Position Sensor Code may include:

• Defective TPS or PPS
• Open or short circuit in a chain between TPS, PPS and PCM
• Corroded electrical connectors
• Defective DBW drive motor.

What are some steps to troubleshoot the P2109?

Check your vehicle information source for technical service bulletins (TSBs) that match the make, model, and engine size of the respective vehicle. The stored symptoms and codes must match as well. Finding a suitable TSB will greatly assist you in your diagnosis.

My diagnosis of code P2109 usually begins with a visual inspection of all wiring and connectors associated with the system. I would also check the throttle valve for signs of carbon build-up or damage. Excessive carbon build-up that keeps the throttle body open at startup may result in code P2109 being stored. Clean any carbon deposits from the throttle body according to the manufacturer's recommendations and repair or replace faulty wiring or components as necessary, then retest the DBW system.

You will need a diagnostic scanner, digital volt / ohmmeter (DVOM), and a reliable source of vehicle information to accurately diagnose this code.

Then connect the scanner to the vehicle diagnostic port and retrieve all stored DTCs. Write them down in case you need information later in your diagnosis. Also save any associated freeze frame data. These notes can be helpful, especially if the P2109 is intermittent. Now clear the codes and test drive the vehicle to make sure the code is cleared.

If the code is cleared immediately, power surges and mismatches between TPS, PPS and PCM can be detected using the scanner data stream. Narrow your data stream to display only relevant data for a faster response. If no spikes and / or inconsistencies are found, use the DVOM to get real-time data on each of the sensor signal wires. To get real-time data from the DVOM, connect the positive test lead to the corresponding signal lead and the ground test lead to the ground circuit, then watch the DVOM display while the DBW is running. Pay attention to voltage surges when slowly moving the throttle valve from closed to fully open. Voltage typically ranges from 5V closed throttle to 4.5V wide open throttle, but check with your vehicle information source for the exact specifications. If surges or other abnormalities are found, suspect that the sensor being tested is defective. An oscilloscope is also a great tool for verifying sensor performance.

If the sensor is working as intended, disconnect all associated controllers and test individual circuits with the DVOM. System wiring diagrams and connector pinouts can help you determine which circuits to test and where to find them on a vehicle. Repair or replace system circuits as necessary.

A faulty PCM or PCM programming error can only be suspected if all sensors and system circuits are checked.

Some manufacturers require the throttle body, throttle actuator motor, and all throttle position sensors to be replaced as a unit.

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