P0135 O2 Sensor Heater Circuit (Bank 1 Sensor 1)

Powertrain Severity: Low Generic OBD-II

Fault in the heater circuit of the upstream oxygen sensor on bank 1.

Common causes

  • Burned-out sensor heater
  • Blown fuse
  • Wiring damage

Symptoms

  • Check engine light
  • Longer time to closed loop after cold start

What to check

  1. Check the heater fuse
  2. Measure heater resistance
  3. Inspect wiring

Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0135, follow the service information for that make and model.

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