P1277 – Air/Fuel Ratio Sensor Heater Fault (Nissan)

Description

The ECM detected a heater malfunction in the AFR sensor on Bank 1.

Want to confirm the real cause of this fault code?

A high-quality OBD2 scanner gives you live data, fuel trims, sensor readings and freeze-frame information — exactly what you need to verify the root cause of this code with confidence.

View Recommended Scanners

Symptoms

  • Long warm‑up
  • Poor drivability

Causes

  • Heater open circuit
  • Shorted wiring
  • Faulty sensor

Diagnosis

  • Check heater resistance
  • Inspect wiring
  • Scan live data

Repair

  • Replace sensor
  • Repair wiring