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2020 TOYOTA CAMRY
2.5L I4•FWD•AUTOMATIC•gas•A25A-FKS
3 active safety recalls on this vehicle — view recalls
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Repairs413Labor479Torque2205Fluid7DTC1947Battery1Maintenance0Recalls3
P0042low severityPowertrain

HO2S Heater Control Circuit (Bank 1 Sensor 3)

on 2020 Toyota Camry 2.5L I4 · FWD

What this code means

The heater control circuit for the third oxygen sensor on bank 1 has a general fault. Sensor heating is impaired, delaying accurate exhaust readings.

Symptoms

  • Check engine light on
  • Failed emissions readiness
  • Minor fuel economy loss

Common causes

  • Faulty O2 sensor heater
  • Blown heater fuse
  • Wiring or connector damage
  • Failed PCM driver

Diagnostic steps

  1. Scan and confirm code
  2. Check heater circuit fuse
  3. Measure heater resistance and voltage
  4. Inspect wiring to sensor 3
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