P0130 code: What it means

Learn what a P0130 code means and how to fix it

A P0130 is defined as: Oxygen Sensor Circuit Malfunction (Bank 1 Sensor 1). This sensor is located on the engine bank that houses the #1 cylinder and is located BEFORE the catalytic converter. The code is telling you that the ECM is seeing an abnormal condition in the circuit to the oxygen sensor, as opposed to the circuit from the oxygen sensor heater.

The PCM sends a reference voltage (usually 5 volts) to the variable resistor in the oxygen sensor and looks for a return voltage. During cranking, it expects to see the full reference voltage return to the PCM since a cold oxygen sensor usually doesn’t alter the incoming reference signal until it heats up. If the PCM doesn’t see the expected return voltage or sees no return voltage, it will set a P0130 code.

The most common causes of a P0130 code

It’s possible the sensor itself is bad. But before replacing it, disconnect the connector to the sensor and check for corrosion or wire harness damage. If that looks good, using a shop manual and wiring diagram, check for the reference voltage and ground inside the connector. If you see both, then the sensor is bad. Replace it.

Typical causes are: bad oxygen sensor, poor connection either at PCM or O2 sensor, or a break in either wire.

TEST: Unplug the connector to the Oxygen sensor. Turn ignition to RUN. Test for specified reference voltage at the connector coming from the PCM. If you see reference voltage, reconnect to the sensor and test for voltage on the signal wire returning to the PCM. If you don’t get a return voltage the sensor is most likely bad.

To learn how to replace an oxygen sensor, click here

© 2012 Rick Muscoplat