P0135 O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1

Definition: The P0135 code indicates a malfunction in the heater circuit of the oxygen sensor located on bank 1, sensor 1. This means that the heating element within the sensor is not functioning properly, which can affect the performance and efficiency of the vehicle’s engine.

p0135 – O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1

Typical Severity: Moderate

Common Causes

P0135: O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1

• Common Causes:
• Faulty oxygen sensor heater circuit
• Open or short in the wiring harness for the oxygen sensor heater circuit
• Poor electrical connection in the oxygen sensor heater circuit
• Fuse related to the oxygen sensor heater circuit is blown or faulty

Common Misdiagnosis

OBD2 Code: P0135

Description: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

Common Misdiagnosis:

• Replacing the oxygen sensor without checking the heater circuit fuse or relay.
• Assuming a faulty sensor when there is actually a wiring issue or poor connection.
• Overlooking potential issues with the engine control module (ECM) that could affect the heater circuit operation.

Common Diagnostic Steps

OBD2 Code: P0135

Description: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

• Check the fuse related to the oxygen sensor heater circuit.
• Inspect the wiring and connectors for damage or corrosion.
• Test the voltage supply to the oxygen sensor heater circuit using a multimeter.
• Verify the ground connection for the oxygen sensor is secure and clean.
• Use an OBD2 scanner to monitor live data and confirm if the heater circuit is functioning properly.
• If necessary, replace the faulty oxygen sensor with a new one.