P0135 in chevy

Decoding the P0135 Code in Your Chevy: Causes and Solutions


Prashant Salla
Prashant Salla5 min read
Decoding the P0135 Code in Your Chevy: Causes and Solutions

Is the check engine light on in your Chevy? If so, there's a chance that the P0135 engine code has been triggered, and you may be wondering what it means and how to resolve it.

The P0135 code is related to your vehicle's oxygen sensor, which is responsible for measuring the oxygen levels in your engine's exhaust gases. When this sensor malfunctions, it can cause the P0135 code to appear and result in a range of engine performance issues.

However, understanding the potential causes of the P0135 code can help you identify the underlying issue and take the necessary steps to resolve it. 

In this article, we'll decode the P0135 code in your Chevy and provide you with some possible causes and solutions to help get your vehicle running smoothly again.

Fixing the P0135 Code with Goodhood

When you face this trouble code when out and about in your Chevy, it'll be handy to have a mobile auto service at your disposal. 

With Goodhood, you can book a qualified mechanic who'll come to your location, inspect either your mechanical or electrical system and diagnose the issue with your car. They'll be able to advise you on what repair or maintenance needs to be done. 

Main Causes of the P0135 Code in Your Chevy

Failed Oxygen Sensor Heater Circuit

A faulty oxygen sensor is your Chevy's most common cause of the P0135 code. The O2 sensor heater circuit measures the oxygen levels in the exhaust gases and relays that information to the engine control module (ECM). If the sensor fails, it can cause the ECM to receive incorrect readings and trigger the code.

Wiring Issues

Another possible cause of the P0135 code is the wiring connecting the oxygen sensor to the ECM. If the wiring is damaged, broken, or frayed, it can cause a weak or inconsistent signal to be sent to the ECM, triggering the code.

Exhaust System Issues

Your Chevy exhaust system is another potential culprit for the P0135 code. If there is a leak or a blockage in the exhaust system, it can cause incorrect readings to be sent to the ECM and trigger the code.

Vacuum Leaks

A vacuum leak is another common cause of the P0135 code. A vacuum leak can cause a lean fuel mixture, which can lead to incorrect readings from the oxygen sensor and trigger the code.

Failed PCM

A failed powertrain control module (PCM) can sometimes cause the P0135 code to appear. The PCM is responsible for managing the vehicle's engine and transmission functions, and if it fails, it can cause a range of issues, including triggering the P0135 code.

It's essential to note that these are just some of the most common causes of the P0135 code. Other factors, such as fuel pressure problems, a clogged fuel filter, or a faulty mass airflow sensor, can also trigger the code. 

Therefore, it's always best to consult a qualified mechanic who can perform a diagnostic scan and pinpoint the underlying issue accurately.

How a Professional Mechanic Inspects and Diagnoses the P0135 Code

When a professional mechanic inspects and diagnoses the P0135 code in your Chevy, they typically follow a set process to identify the underlying issue accurately.

Here are the steps that a mechanic may take to diagnose the P0135 code:

Scan the Vehicle's Onboard Diagnostic System

The first step in diagnosing the P0135 code is to scan the vehicle's onboard diagnostic system using a diagnostic tool. The tool will retrieve the code and any other relevant diagnostic trouble codes (DTCs) that may provide more insight into the issue.

Inspect the Oxygen Sensor

Once the code is retrieved, the mechanic will inspect the oxygen sensor to determine if it's functioning correctly. They may use a multimeter to test the sensor's voltage output or a scan tool to monitor the sensor's readings in real-time.

Check the Wiring and Connections

If the oxygen sensor functions correctly, the mechanic will inspect the wiring and connections between the sensor and the ECM. They will look for signs of damage, such as frayed wires or corroded connections, and test the circuit for continuity.

Inspect the Exhaust System

If the wiring and connections appear to be functioning correctly, the mechanic will inspect the exhaust system for leaks or blockages that may be causing the issue.

Check for Vacuum Leaks

If there are no issues with the exhaust system, the mechanic will inspect the engine's vacuum system for leaks that may be causing the P0135 code.

Check the Powertrain Control Module (PCM)

Finally, if none of the above steps have identified the issue, the mechanic may inspect the powertrain control module to determine if it's functioning correctly. They may perform a series of tests on the PCM, including checking the power and ground circuits, testing the input and output signals, and ensuring that the PCM appropriately communicates with the other vehicle systems.

Once the mechanic has identified the underlying issue, they will provide the vehicle owner with a repair estimate and perform any necessary repairs or replacements to resolve the issue.

It's essential to note that the diagnostic process may vary depending on the make and model of the vehicle, so it's always best to consult a qualified mechanic with experience working on Chevy vehicles.

Conclusion

The P0135 code in a Chevy can be caused by several issues, including a faulty oxygen sensor, wiring problems, exhaust system issues, and vacuum leaks.

Remember to always consult professional mobile auto service like Goodhood when dealing with car-related issues, as it's essential to ensure that the underlying cause is identified and resolved appropriately. Doing so will help you avoid even more costly repairs down the road.

Frequently Asked Questions

What does the P0135 code mean in a Chevy?

The P0135 diagnostic trouble code indicates a bad oxygen sensor. This sensor measures the oxygen levels in the engine's exhaust gases. If this sensor malfunctions or fails, it can trigger the P0135 code.

What are some of the most common causes of the P0135 code in a Chevy?

The most common causes of the P0135 code in a Chevy include a failed heated oxygen sensor, wiring issues, exhaust system problems, vacuum leaks, and a failed powertrain control module (PCM).

Does the catalytic converter heating circuit have anything to do with the P0135 code?

Yes, a failed catalytic converter heating circuit can cause the P0135 code to be triggered. The catalytic converter helps reduce the amount of air pollution created by your vehicle's exhaust gases, and its internal heating element helps keep it running efficiently. The heating circuit connects the converters to the engine control module, and if it fails, it can cause incorrect readings from the sensor and trigger the P0135 code.

How does a professional mechanic diagnose the P0135 code?

When a professional mechanic diagnoses the P0135 code, they typically follow a set process to pinpoint the underlying issue. This process involves scanning the vehicle's onboard diagnostic system, inspecting the oxygen sensor and wiring, inspecting the exhaust system for leaks or blockages, checking for vacuum leaks, and inspecting the powertrain control module (PCM).

Once the mechanic has identified the underlying issue, they will provide a repair estimate and perform any necessary repairs or replacements.

Is it safe to drive with the P0135 code?

It's generally not recommended to drive with the P0135 code, as it can cause a range of engine performance issues and risk further damage to your vehicle. Therefore, it's best to have the issue diagnosed and resolved by a qualified mechanic as soon as possible. Doing so will help ensure that your vehicle is running safely and efficiently.