Back to 2005 Mazda B2300

2005 MAZDA B2300

2.3L I4FWDAUTOMATICgas
Repairs0Labor593Torque2361Fluid6DTC803Battery0Maintenance0Recalls0
P0036low severityPowertrain

HO2S Heater Control Circuit Bank 1 Sensor 2

on 2005 Mazda B2300 2.3L I4 · FWD

What this code means

The PCM detected a malfunction in the heater circuit of the downstream heated oxygen sensor (Bank 1, Sensor 2).

Symptoms

  • Check Engine Light
  • Failed emissions test
  • Poor catalyst monitoring

Common causes

  • Faulty O2 sensor heater
  • Blown fuse
  • Wiring issue

Diagnostic steps

  1. Check fuse
  2. Test heater resistance
  3. Inspect wiring
  4. Check PCM output

Repair notes

Replace downstream O2 sensor or repair wiring.

Other Powertrain codes on this vehicle

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