P0050
HO2S Heater Control Circuit Bank 2 Sensor 1
Emissions / O2 sensor
Generic OBD-II
Medium
What it means
P0050 means the ECM has detected a fault in the heater control circuit of the upstream oxygen sensor on bank 2 (sensor 1). The heater brings the sensor to temperature quickly so it can read accurately soon after start-up. The engine still runs normally, but the car takes longer to reach closed-loop fueling and won't pass an emissions test until the heater circuit is repaired.
Medium
Can I keep driving? Safe to drive — the fault is in the sensor's heater circuit, so it mainly delays closed-loop fueling and affects emissions, not how the car runs.
Common symptoms
What you'll notice
- Check-engine light on
- Will fail an emissions/readiness test
- Slightly worse fuel economy until the sensor warms up
Common causes
Most likely first
- Failed heater element inside the bank 2, sensor 1 oxygen sensorLikely
- Corroded or damaged wiring/connector in the heater circuitCommon
- Blown O2 heater fuseCommon
- Failed ECM driver (least likely)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the upstream (bank 2, sensor 1) O2 sensor connector and heater wiring.
- Check the O2 heater fuse and the heater circuit for an open or short.
- Measure the sensor's heater resistance; replace the sensor if the element is open or out of spec.
- Consider the ECM driver only after wiring, fuse and sensor test good. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0050?+
Yes. Drivability is normal; the effects are a slower warm-up to closed-loop and an emissions-test failure.
Can I just clear P0050?+
It returns once the heater circuit is re-tested. Replace the sensor or repair the wiring to clear it for good.
Related codes
Often seen with P0050
Read & clear P0050 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