P0057
HO2S Heater Control Circuit Low Bank 2 Sensor 2
Oxygen sensor heater
Generic OBD-II
Medium
What it means
P0057 means the heater circuit for the downstream oxygen sensor on Bank 2, Sensor 2 is reading low — usually a short to ground or open in the heater wiring or a failed heater element. The heater brings the sensor up to operating temperature quickly so it can read exhaust oxygen. The engine still runs normally; the real effect is on emissions monitoring, so the code mainly matters for passing an emissions test.
Medium
Can I keep driving? Yes — the car drives normally; this downstream O2 sensor heater mainly affects emissions readiness and monitoring, not how the engine runs.
Common symptoms
What you'll notice
- Check-engine light on
- Emissions readiness monitors won't complete (can fail an emissions test)
- Slightly increased emissions until the sensor reaches temperature
Common causes
Most likely first
- Failed oxygen sensor heater element (Bank 2, Sensor 2 — downstream)Likely
- Open or short-to-ground (low) in the heater control wiring or connectorCommon
- Loose or corroded connection, or a blown heater fuseCommon
- Failed ECM heater driver (rare)Less often
How to diagnose & fix
Work through it in order
- Confirm the code and check the sensor's heater fuse and connector.
- Measure the heater element's resistance across the sensor's heater pins.
- Inspect the control wiring for a short to ground or an open circuit.
- Replace the downstream O2 sensor if the heater element is open or out of spec.
- Repair wiring, clear the code, and run a drive cycle to confirm monitors complete.
FAQ
Quick answers
Is it safe to drive with P0057?+
Yes — it won't leave you stranded. The main downsides are a failed emissions test and slightly higher emissions until fixed.
Can I just clear P0057?+
It clears, but returns once the heater circuit fails again, and readiness monitors stay incomplete until the fault is repaired.
Related codes
Often seen with P0057
Read & clear P0057 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