P0155 O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Definition: The P0155 code indicates that the heater circuit of the oxygen sensor located in bank 2, sensor 1 is malfunctioning. This means there is an issue with the heating element within the sensor, which helps it reach its operating temperature quickly.

p0155: O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Typical Severity: Moderate

Common Causes

P0155 – O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Common causes of this OBD2 code include:

• Faulty oxygen sensor heater circuit
• Open or short in the wiring harness connected to the oxygen sensor heater circuit
• Poor electrical connection related to the oxygen sensor heater circuit
• Fuse related to the oxygen sensor heater circuit is blown or faulty
• Faulty Engine Control Module (ECM) or Powertrain Control Module (PCM)

 

Common Misdiagnosis

OBD2 Code: P0155

Description: O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)

Common Misdiagnosis: Replacing the oxygen sensor without checking for issues in the wiring or fuse related to the heater circuit.

 

Common Diagnostic Steps

OBD2 Code: P0155

Description: O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)

• Check the oxygen sensor heater circuit fuse and replace if blown.
• Inspect the wiring and connectors for damage or corrosion in the heater circuit of Bank 2, Sensor 1.
• Test the resistance of the oxygen sensor’s heater element using a multimeter to ensure it is within specifications.
• Verify that there is proper voltage supply to the oxygen sensor’s heater circuit when the engine is running.
• Use an OBD2 scanner to clear the code and perform a test drive to see if it returns.
• If all checks are normal, consider replacing the oxygen sensor on Bank 2, Sensor 1.