OBD-II DTC P0135 – O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
DTC P0135 meaning
DTC P0135 refers to a diagnostic trouble code indicating that the Engine Control Module (ECM) has detected a problem with the oxygen sensor circuit for Bank 1 Sensor 1. This sensor is typically located before the catalytic converter and is responsible for monitoring the level of oxygen in the exhaust gases. The “No Activity Detected” message suggests that the ECM is not receiving a signal from the sensor, which can affect fuel efficiency and emissions control.
DTC P0135 symptoms
Common symptoms associated with DTC P0135 may include:
- Check Engine Light illuminated
- Poor fuel economy
- Rough engine idle
- Increased emissions
- Failed emissions test
DTC P0135 causes
Several factors can lead to the occurrence of DTC P0135, including:
- Faulty oxygen sensor
- Wiring issues or damaged connectors
- Exhaust leaks
- Faulty ECM
- Corrosion or poor connections in the sensor circuit
DTC P0135 seriousness
DTC P0135 is considered a serious issue as it can lead to:
- Increased fuel consumption
- Higher emissions, potentially causing environmental harm
- Potential damage to the catalytic converter if not addressed
- Failure to pass emissions testing
How to diagnose DTC P0135
To diagnose DTC P0135, follow these steps:
- Use an OBD-II scanner to confirm the code and check for any additional codes.
- Inspect the oxygen sensor and its wiring for visible damage or corrosion.
- Test the voltage and ground signals at the oxygen sensor connector.
- Check for exhaust leaks that may affect sensor readings.
- Verify the operation of the ECM and its ability to process sensor signals.
How to fix DTC P0135 step-by-step instructions
To fix DTC P0135, follow these steps:
- Inspect and repair any damaged wiring or connectors related to the oxygen sensor.
- Replace the faulty oxygen sensor if it is determined to be defective.
- Seal any exhaust leaks that may be present.
- Clear the DTC using an OBD-II scanner.
- Test drive the vehicle to ensure the code does not return and monitor for proper sensor operation.
How to erase DTC P0135
To erase DTC P0135, follow these steps:
- Connect an OBD-II scanner to the vehicle’s diagnostic port.
- Turn on the ignition without starting the engine.
- Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
- Confirm the action to clear the trouble codes.
- Disconnect the scanner and start the vehicle to check if the code reappears.
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