What Does Engine Code P0138 Mean

P0138 Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)

The oxygen sensor circuit high voltage (bank 1 sensor 2) code is a generic OBD-II trouble code. It means that the oxygen sensor on bank 1, sensor 2 is reading a higher voltage than expected. This can be caused by a number of things, including a bad oxygen sensor, a wiring problem, or a problem with the engine’s computer.

So What Does Engine Code P0138 Mean?

P0138 is a generic OBD-II code that indicates that the oxygen sensor heater circuit for Bank 1 Sensor 2 is malfunctioning. This code is typically caused by a faulty oxygen sensor, a wiring issue, or a problem with the PCM.

What Does Engine Code P0138 Mean?

Engine code P0138 is a generic OBD-II code that indicates that the oxygen sensor heater circuit for the downstream oxygen sensor (sensor 2) on the exhaust manifold is malfunctioning. This code is set when the powertrain control module (PCM) detects that the heater circuit is not providing the specified amount of current to the oxygen sensor.

Symptoms

Symptoms of a P0138 code may include:

A check engine light on the dashboard
Reduced engine performance
Rough idle
Increased fuel consumption
Poor acceleration

Causes

There are a number of possible causes for a P0138 code, including:

A faulty oxygen sensor heater
A damaged wiring harness for the oxygen sensor heater
A problem with the PCM

Diagnosis

A P0138 code can be diagnosed by a qualified technician using a scan tool. The technician will first connect the scan tool to the vehicle’s OBD-II port and retrieve the diagnostic trouble codes (DTCs). The technician will then use the scan tool to monitor the oxygen sensor heater circuit for any malfunctions.

Repair

Once the cause of the P0138 code has been diagnosed, the technician will be able to make the necessary repairs. Repairs may include replacing the oxygen sensor heater, repairing the wiring harness for the oxygen sensor heater, or replacing the PCM.

Prevention

There are a few things you can do to help prevent a P0138 code from occurring, including:

Keeping your vehicle’s engine oil level topped off
Inspecting your vehicle’s exhaust system for leaks
Avoiding driving through deep water

Conclusion

A P0138 code is a serious problem that can lead to reduced engine performance and increased fuel consumption. If you have a P0138 code, it is important to have it diagnosed and repaired as soon as possible.

Also Read: What Does Engine Code P0141 Mean