P0138 Code – Symptoms & Causes

Automobile sector has been developed with advanced electrical & electronic technologies. Sensors, Actuators & Ciruits are responsible for delivering the actual functioning parameters of vehicle’s components to the Control Module.

Engine Control Module decides what to do further after receiving the signal from such sensor circuits on the basis of specified voltage resistance.

If one of the components fails to work properly then sensor sends such signal to ECM. ECM detects that signal as a fault & Illuminate the Check Engine Light. We understand that problem by diagnosing it with the scanning tool.

Vehicle’s problems are stored as DTCs. These trouble codes have to be well understood by their symptoms & Causes. In that regard, We have discussed Symptoms & Causes of Code P0138.

What is Code P0138 –

Code P0138 represents the Problem related to O2 Sensor (Bank 1, Sensor 2) which is actually a high voltage signal from O2 Sensor.

This O2 sensor determines & analyzes the the amount of oxygen in vehicle’s Exhaust means that its working is to analyse the vapors from catalytic converter.

If any trouble found about air-fuel amount inside the engine then this sensor signals the high voltage to the Control Module. High voltage means your vehicle runs on high Fuel amount & less air.

Symptoms of Code P0138

• Check Engine Light

• Poor Fuel Economy

• Smell from Exhaust

• Rough Idle

Check Engine Light is a common symptom that any trouble code shows. Other signs are developed due to higher Amount of fuel is burning inside the combustion chamber with less presence of oxygen.

Causes of Code P0138

• Faulty Oxygen Sensor

• Damaged Wiring

• Faulty Catalytic Converter

• High Fuel Pressure

Fixing procedure is always related with Causes. If you understand the reasons behind any trouble code then diagnosing it would be easier procedure for you.

Intially you have to remove additional trouble codes. Then Inspect O2 Sensor & It’s Circuit for any Damages around.

If you didn’t find any fault then go for checking the voltage resistance. It will make you sure about replacing the sensor. Before making any replacement, Be sure about working ranges of coolant Temperature & Fuel Pressure.

If you really liked this article, P0138 Code – Symptoms & Causes, Leave your opinion in the comment box…

Leave a Comment