The correct operation of the engine depends on the ideal air / fuel ratio, which is 14.7: 1. To have this relationship, the ECM (Engine Control module) takes the readings of the Oxygen Sensors (O2).
Oxygen Sensors (O2) are the ones that detect the amount of oxygen in the exhaust, then send that information to the Engine Control Module (ECM) who uses that information to adjust the amount of fuel delivered to the engine.
The Oxygen Sensor is equipped with a heating element that heats the O2 more quickly than the exhaust gases. In this way, the time necessary for the engine to enter a closed cycle is reduced, and emissions are minimized. This heating element has a voltage supply of 12 volts and a ground that controls the ECM.
In the event that the ECM detects a fault in the heater circuit of the Oxygen Sensor number 1 located in bank number 1, the DTC code P0030 OBD2 is established.