P0055 - HO2S Heater Resistance (Bank 1 Sensor 3)

The PCM detected a heater-control or heater-resistance problem in the heated oxygen sensor circuit, which can delay sensor warm-up and emissions readiness.

Code Overview

The PCM detected a heater-control or heater-resistance problem in the heated oxygen sensor circuit, which can delay sensor warm-up and emissions readiness.

Common Causes

• Failed O2 sensor heater element
• Blown fuse or relay issue
• Harness damage near exhaust
• Poor power or ground to the heater circuit

Diagnostic Steps

1. Inspect the O2 sensor harness near the exhaust for heat damage
2. Check the heater fuse, relay, and power supply
3. Measure heater resistance and compare against spec if available
4. Verify the PCM can control the heater circuit before replacing the sensor

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

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Next Steps

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