DTC codes / P21xx · Fuel and air metering / P2109
P2109 means the engine computer has detected that the throttle body's internal 'A' position sensor is not reaching its expected minimum mechanical stop, so the learned closed-throttle reference point is out of range. The computer compares the sensor voltage at key-on and during closed-throttle operation against a factory-programmed minimum limit and sets this code when the signal stays too high or too low.
Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.
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