Setting DTC P2240 OBDII code indicates that the Powertrain Control Module (PCM) has encountered a positive current inconsistency from the Oxygen sensor (O2) sensor number 1 on bank 2. This sensor is located in front of the Catalytic Converter (TWC) and its positive current control circuit is a low voltage circuit.
To monitor the amount of oxygen that is present in the exhaust of each bank of the engine, the PCM uses the input data from the O2 Sensors. In addition, this information is used to check that the TWC is working properly.
The voltage signal outputs from the Oxygen Sensors are lower when there is a considerable amount of oxygen in the exhaust. But these voltage signals are higher when there is less oxygen in the exhaust. In case an out-of-range voltage is detected, the fault code P2240 OBD2 is set.