P0064
HO2S Heater Control Circuit High Bank 2 Sensor 3
Emissions / O2 sensor
Generic OBD-II
Medium
What it means
P0064 means the ECM has seen high voltage in the heater control circuit of the bank 2, sensor 3 oxygen sensor — a downstream sensor used mainly to monitor the catalytic converter. Because this sensor doesn't control fueling, the engine runs normally, but the fault sets the check-engine light and will keep the car from passing an emissions test until the heater circuit is repaired.
Medium
Can I keep driving? Safe to drive — this is a downstream sensor's heater circuit, so it affects emissions monitoring, not how the car runs.
Common symptoms
What you'll notice
- Check-engine light on
- Will fail an emissions/readiness test
- No noticeable change in how the engine runs
Common causes
Most likely first
- Failed heater element inside the bank 2, sensor 3 oxygen sensorLikely
- Short to voltage or open in the heater control wiringCommon
- Blown O2 heater fuseCommon
- Corroded or loose sensor connectorLess often
- Failed ECM driver (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the bank 2, sensor 3 (downstream) O2 sensor connector and heater wiring.
- Check the O2 heater fuse and the heater circuit for a short to voltage or an open.
- Measure the sensor's heater resistance; replace the sensor if the element is out of spec.
- Consider the ECM driver only after the wiring, fuse and sensor test good. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0064?+
Yes. This downstream sensor's heater fault doesn't change drivability; its main impact is failing an emissions test.
Can I just clear P0064?+
It returns when the heater circuit is re-tested. Repair the wiring or replace the sensor to clear it for good.
Related codes
Often seen with P0064
Read & clear P0064 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX