P2243 - O2 SENSOR REFERENCE VOLTAGE CIRCUIT / OPEN BANK 1 SENSOR 1

Oxygen Sensor (O2) number 1 is found in the exhaust manifold. Its main function is to detect the total of oxygen in the exhaust gas compared to the outside air. The O2 sensors have a zirconium ceramic tube which generates approximately 1 volt in rich conditions and 0 volts in leaner conditions.

The Powertrain Control Module (PCM) receives the signal from the Oxygen Sensor, with which it adjusts the duration of the injection pulse, thus achieving the stoichiometric air/fuel ratio.

When the diagnostic code P2243 OBD2 is stored, it means that the PCM detected that the O2 Sensor 1 of bank 1 has an open circuit for the reference voltage.

• Check Engine lights on.
• Low fuel mileage.
• Engine loses power.
• Black smoke is expelled from the exhaust.

Common causes of the P2243 OBDII fault code are:

• Maybe some Oxygen Sensor wiring is bad.
• Perhaps an O2 Sensor electrical connector is corroded.
• There may be exhaust leaks.
• The Oxygen Sensor may be defective.

To troubleshoot the DTC P2243 OBD2 code you should consider the following advice:

• Check the wires leading to the Oxygen Sensor. Check each of these components for damage due to burns or wear. Repair or replace as necessary.
• Check the electrical connector on the O2 Sensor for corrosion. It should be cleaned if required.
• Check that the battery voltage supply circuit has the proper resistance level. A lack of resistance warrants the replacement of the sensor.