The P2224 code indicates that the engine control module has detected a voltage signal that is higher than the expected range from the NOx sensor heater sense circuit on Bank 2. This typically points to an open circuit or a failure in the internal heating element of the sensor.
The internal heating element of the NOx sensor has failed or developed an open circuit.
Frayed, broken, or burnt wires in the heater sense circuit creating an open connection.
Moisture or corrosion at the sensor electrical connector causing a loss of continuity.
A blown fuse in the sensor heater circuit preventing the element from receiving power.
An internal failure in the engine control module's sensing circuit (highly uncommon).
Generally, no. P2224 typically does not trigger a limp mode, though it will prevent the vehicle from passing an emissions inspection.
The sensor is the most likely failure point, but the wiring harness should be inspected first to ensure the new sensor is not damaged by a short or open circuit in the loom.
No. It is very rare for the PCM to be the cause of P2224; the issue is almost always found at the sensor itself or the associated wiring.