Galant Late Model Mitsubishi Galant Code 15 stored in ECM memory - Idle Motor Position Sensor CAUSE: Code 15 is set if the Idle Motor Position Sensor (MPS) is out of range as compared to the Throttle Position Sensor (TPS). DIAGNOSIS: Most common failures are faulty idle speed adjusting procedures, carbon build-up on throttle plates, defective idle switch contacts or a faulty sensor. With the engine in Park or Neutral and at operating temperature, and all electrical loads Off , the MPS voltage should be between 500 to 1300mV (milliVolts). With the A/C ON, the value should increase to 800 to 1800mV, and in Drive with the A/C ON, should be between 900 and 1900mV. Visit our Resource Library for available downloads