2111 Engine speed sender. (RPM)
2113 Hall sender - No speed signal from distributor; check Hall sensor and circuit.
Air-flow sensor plate is not moving freely; adjust potentiometer or lever.
2231 Idle-speed stabilizer adjustment limits exceeded; too-fast idle. Adjust throttle for full closing, check for vacuum leak, check ignition timing.
Or Air Mass Sensor - Check sensor and wiring.