OBD Guide

P0155

O2 Sensor Heater Circuit Bank 2 Sensor 1

P0155 is an OBD-II diagnostic trouble code meaning: O2 Sensor Heater Circuit Bank 2 Sensor 1. Common causes: open or short circuit in the sensor heating circuit, malfunction of the oxygen sensor itself. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Increased fuel consumption
  • Unstable engine operation at idle
  • Reduced engine power
  • Check Engine Light Illuminates

Causes

  • Open or short circuit in the sensor heating circuit
  • Malfunction of the oxygen sensor itself
  • Problems in the wiring harness or connectors
  • Faulty heating circuit relay or fuse
  • Problems with the engine control unit (ECU)

How to Fix

  1. Check the integrity of the sensor heating circuit (resistance and voltage)
  2. Inspect the wiring harness and connectors for damage.
  3. Check the fuse and relay of the heating circuit
  4. If necessary, replace the oxygen sensor
  5. Clear error memory and check if code is returned

Related codes

Error P0155 by Vehicle Brand

FAQ

What does the P0155 code mean?

P0155 is an OBD-II diagnostic trouble code that indicates: O2 Sensor Heater Circuit Bank 2 Sensor 1

What causes a P0155 error code?

The most common causes of P0155 include: Open or short circuit in the sensor heating circuit; Malfunction of the oxygen sensor itself; Problems in the wiring harness or connectors; Faulty heating circuit relay or fuse.

How do I fix a P0155 diagnostic trouble code?

To fix P0155: Check the integrity of the sensor heating circuit (resistance and voltage). Inspect the wiring harness and connectors for damage.. Check the fuse and relay of the heating circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0155?

Limited driving only, diagnose soon

How much does it cost to fix P0155?

The estimated repair cost for P0155 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat