Error code

OBD2 P0155

OBD2P0155
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

O2 Sensor Heater Circuit.

Severity

moderateCan drive, but may fail emissions tests.

Summary

P0155 indicates a malfunction in the heater circuit of the oxygen sensor (HO2S) on bank 2, sensor 1. This affects the engine's ability to control fuel mixture accurately.

Symptoms

  • Illuminated check engine light
  • Potential failure during emissions testing

Common Causes

  • Problem on the ground side of the O2 sensor heater circuit
  • Problem on the power side of the O2 sensor heater circuit
  • High resistance in the O2 sensor heater element
  • Open circuit in the O2 sensor heater element

Diagnosis

  1. Test the heater circuit wiring for power and ground using a multimeter.
  2. Check the resistance of the sensor heating element to determine if it has high resistance or an open circuit.

Fixes

  • Replace faulty O2 sensor

FAQ

What does P0155 mean?

P0155 indicates a malfunction in the heater circuit of the oxygen sensor on bank 2, sensor 1.

How do I diagnose P0155?

Diagnose by testing the power and ground sides of the O2 sensor heater circuit using a multimeter.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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