P2109: Learned throttle minimum position outside the permitted window

P2109 concerns throttle-position minimum-stop performance. Mazda's SKYACTIV-G monitor checks the fully closed throttle position even after closed-position learning has completed.

What the learned value reveals

The documented failure limits are a fully closed reading of 5.1 degrees or lower, or 15.9 degrees or higher. These are Mazda's reported position values, not an instruction to set the throttle mechanically to a particular angle. The learning-complete condition is important: simply assuming that a relearn has not run misses what this monitor actually evaluates.

The protective response limits maximum engine speed and fixes throttle opening. Those actions can affect acceleration, but the DTC alone does not identify a failed accelerator pedal. Mazda's fault list and procedure concentrate on the throttle body, its actuator circuit and the PCM.

Distinguish wiring from movement

After related DTCs are assessed, the sequence checks throttle-body and PCM connections and the actuator control circuit for grounded, powered or open faults. It then evaluates throttle operation and the actuator itself. A correct electrical supply does not establish that the valve moves properly; conversely, an abnormal position reading does not prove a mechanical obstruction.

Verification uses the specified key-on or running self-test and a pending-fault check. Throttle actuation should be tested with the factory procedure and suitable precautions, particularly because its fail-safe changes engine response. Diagnose the detected position error before selecting a replacement assembly.

Documented application

Mazda3 workshop manual 01/2019 onward, d9n1-1a-22d_ver10; PCM (SKYACTIV-G). Verify exact vehicle specification; this is a Mazda application example. Mazda factory diagnostic page, mirrored by CHARM.