Error Code P0135
Moderate Issue
DTC Code P0135 indicates an O2 Sensor Heater Circuit Malfunction for Bank 1 Sensor 1. This code is triggered when the Engine Control Module (ECM) detects that the Heated Oxygen Sensor (HO2S) 1 heater current is out of factory specifications, affecting the sensor's ability to reach and maintain the necessary operating temperature for accurate readings.
What symptoms indicate Error Code P0135?
- Engine Light ON: The check engine light or service engine soon warning light illuminates, indicating a potential issue with the O2 sensor heater circuit.
- Higher Fuel Consumption: The vehicle may experience increased fuel consumption due to the O2 sensor not reaching optimal operating temperature, affecting fuel mixture adjustments.
What causes OBD code Error Code P0135?
- The heated oxygen sensor may be faulty, leading to incorrect readings and triggering the error code.
- An open or shorted harness in the sensor can disrupt the electrical flow, causing a malfunction.
- Poor electrical connections in the sensor circuit can result in intermittent or failed sensor operation.
- A blown fuse in the sensor circuit can prevent the heater from functioning, leading to the error code.
- A malfunctioning Engine Control Module (ECM) can misinterpret sensor data, causing the error code to appear.
How to fix OBD code Error Code P0135?
- Initial Inspection: Visually inspect the heated oxygen sensor (HO2S) and its wiring for any signs of damage, corrosion, or disconnection. Pay special attention to the connectors and wiring harness.
- Check the HO2S Fuse: Locate and inspect the fuse related to the heated oxygen sensor circuit. Ensure it is not blown. Replace if necessary.
- Test the Heater Circuit: Using a multimeter, measure the resistance of the heater element in the O2 sensor. Compare the reading to the manufacturer's specifications. A high or infinite resistance indicates a faulty heater element.
- Inspect for Water Intrusion: Check for any signs of water intrusion in the sensor connector. Moisture can cause short circuits and lead to fuse failure.
- Check Power and Ground: Verify that the sensor is receiving proper voltage and ground. Use a multimeter to check the voltage supply to the heater circuit.
- Replace the O2 Sensor: If all previous checks are satisfactory and the issue persists, replace the Bank 1 Sensor 1 O2 sensor with a new one.
- Clear DTC and Test Drive: Clear the diagnostic trouble code and perform a test drive to ensure the issue is resolved and the code does not return.