P0030 - HO2S HEATER CONTROL CIRCUIT (BANK 1 SENSOR 1)

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.

• Check Engine light turns on.
• Increase the time to enter the closed cycle.

The factors that lead to the establishment of fault code P0030 are:

• Short circuit to earth of the heating element of the Oxygen Sensor (O2).
• Circuit feeding the O2 heating element in short.
• High resistance in the heating element of the O2.
• The heating element of the Oxygen Sensor (O2) may be defective.

To correct the faults caused by diagnostic code P0030 you must do the following:

• Perform a visual inspection of Oxygen Sensor (O2) located in bank number 1. Verify that the cables that lead to it are in good condition. If not, correct any defect in these. Also, if you notice damage in the O2 you must change it.
• In case the visual inspection does not cause problems, you must measure the heater circuit of the Oxygen Sensor. For this, you must have a scanning tool. If in the data flow of your scanner shows that the O2 Sensor heater has 0 amps, it means that there is a short circuit. Therefore, make sure there are no fuses burned.
• With the switch in the ignition position, use a voltmeter with which you must verify the power supply of the battery, this must be 12 volts to the heating element. If this is not the voltage present, it is indicative that there is a short in the supply circuit. Repair it and take into account that you must change the fuses that have come out of the short circuit.
• If there is no problem when inspecting the supply circuit, you must remove the earth circuit from the wiring connector of the Engine Control module and check the resistance in the circuit. If the resistance is infinite, there is an open circuit. Repair it.
• Even after all these tests have been carried out and the problem persists, changes the Oxygen Sensor.