how to fix P0135 oxygen sensor issue on GMC Sierra T1XX (2019-Present)

GMC Sierra T1XX (2019-Present)

Error Codes

1-2 hours

Time

medium

Difficulty

medium

Severity

Error Code: P0135

3 min read

500 words

Problem Statement

Learn how to diagnose and fix P0135 oxygen sensor issue in GMC Sierra T1XX. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code

P0135

Affected Component

Exhaust System

Estimated Time

1-2 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems.
•Allow the engine to cool before working on any components.

Symptoms

•Check engine light illuminated
•Poor fuel economy
•Rough idle
•Increased emissions
•Engine stalling during acceleration

Diagnostic Steps

1
Scan the vehicle using an OBD-II scanner to confirm the P0135 error code.
2
Inspect the wiring and connectors leading to the oxygen sensor for any visible damage or corrosion.
3
Check the fuse related to the oxygen sensor circuit.
4
Measure the voltage output of the oxygen sensor using a multimeter while the engine is running.
5
Verify the engine temperature is within the normal operating range for sensor function.
6
Inspect the exhaust system for leaks that could affect oxygen sensor readings.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II scanner
•Socket wrench set (including oxygen sensor socket)
•Multimeter
•Electrical contact cleaner
•Torque wrench

Parts Required

•New upstream oxygen sensor
•Anti-seize compound (if not pre-applied)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Scan the vehicle using an OBD-II scanner to confirm the P0135 error code.
2
Inspect the wiring and connectors leading to the oxygen sensor for any visible damage or corrosion.
3
Check the fuse related to the oxygen sensor circuit.
4
Measure the voltage output of the oxygen sensor using a multimeter while the engine is running.
5
Verify the engine temperature is within the normal operating range for sensor function.
6
Inspect the exhaust system for leaks that could affect oxygen sensor readings.

Solution

1. Preparation

Gather necessary tools and parts.
Disconnect the battery to ensure safety.
Allow the engine to cool if it has been running.

2. Remove the Old Oxygen Sensor

Locate the upstream oxygen sensor on the exhaust manifold.
Use a socket wrench (usually a 22mm oxygen sensor socket) to unscrew the old oxygen sensor.
Carefully remove the sensor and disconnect the electrical connector.

3. Inspect and Clean

Inspect the oxygen sensor connector for any signs of corrosion or damage.
If necessary, clean the connector with electrical contact cleaner.
Inspect the wiring harness for any signs of wear or fraying.

4. Install New Oxygen Sensor

Apply anti-seize compound to the threads of the new oxygen sensor (if not pre-applied).
Carefully install the new oxygen sensor by hand to avoid cross-threading, then tighten it with the socket wrench to the manufacturer’s specified torque (typically around 30 lb-ft).
Reconnect the electrical connector securely.

5. Reconnect Battery and Test

Reconnect the battery terminals securely.
Start the engine and allow it to reach operating temperature.
Monitor the engine performance and check for any new error codes using the OBD-II scanner.