HO2S Heater Control Circuit (Bank 2 Sensor 3)
P0062 indicates the oxygen sensor heater circuit for Bank 2 Sensor 3 (downstream sensor after the catalytic converter) is not functioning properly. The heater element in this sensor fails to reach operating temperature quickly during cold starts, preventing the sensor from sending accurate readings to the engine control module.
What You Might Notice
- Check Engine Light (MIL) illumination
- No noticeable drivability symptoms
- Sensor may take longer to warm up after cold start
- Possible slight increase in emissions
- No effect on engine performance or fuel economy
Most Common Causes
- 1
Open or shorted heater circuit wiring
Damaged, corroded, or disconnected wiring to the B2S3 oxygen sensor heater element, preventing current flow to heat the sensor.
- 2
Failed oxygen sensor heater element
The internal heating element inside Bank 2 Sensor 3 has burned out or degraded, making it unable to generate heat when powered.
- 3
Blown heater fuse or faulty relay
The dedicated fuse or relay controlling the B2S3 heater circuit is open or defective, cutting power to the sensor heater.
- 4
Engine control module (ECM) malfunction
The ECM is unable to supply proper voltage or signal to the B2S3 heater circuit due to internal failure or software issue.
How to Diagnose It
- 1
Check Open or shorted heater circuit wiring — Damaged, corroded, or disconnected wiring to the B2S3 oxygen sensor heater element, preventing current flow to heat the sensor.
- 2
Check Failed oxygen sensor heater element — The internal heating element inside Bank 2 Sensor 3 has burned out or degraded, making it unable to generate heat when powered.
- 3
Check Blown heater fuse or faulty relay — The dedicated fuse or relay controlling the B2S3 heater circuit is open or defective, cutting power to the sensor heater.
- 4
Check Engine control module (ECM) malfunction — The ECM is unable to supply proper voltage or signal to the B2S3 heater circuit due to internal failure or software issue.
How to Fix It
- 1
Inspect and repair heater circuit wiring
Check the wiring harness and connectors leading to Bank 2 Sensor 3 for corrosion, damage, or loose connections. Repair or replace damaged wiring and ensure proper connector seating.
- 2
Replace oxygen sensor B2S3
If wiring is intact, the sensor's internal heater element has likely failed. Remove and replace the Bank 2 Sensor 3 oxygen sensor with a new unit.
- 3
Check and replace heater circuit fuse or relay
Locate the fuse or relay controlling the B2S3 heater in the engine bay fuse box. Test continuity; if open, replace with a new fuse or relay of the same amperage rating.
- 4
Diagnose ECM output signals
Use a multimeter or scan tool to verify the ECM is sending proper voltage to the B2S3 heater circuit. If voltage is absent at the connector, the ECM may require reprogramming or replacement.
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