P0051low severityPowertrain

HO2S Heater Control Circuit Low Bank 2 Sensor 1

on 2002 Infiniti QX4 3.3L V6 · RWD

What this code means

Low voltage in the Bank 2 Sensor 1 O2 heater circuit.

Symptoms

  • Check Engine Light
  • Extended warmup emissions

Common causes

  • Short to ground
  • Faulty sensor
  • Corroded connector

Diagnostic steps

  1. Test voltage
  2. Check for shorts
  3. Test resistance

Repair notes

Repair or replace sensor.

Other Powertrain codes on this vehicle

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