P0057 fault code: HO2S Heater Control Circuit Low
We have no verified driving guidance for P0057. Escalated: do not drive until that low downstream heater is checked. Stop if the lamp flashes.
Can I DIY?
Professional-only boundary. Scanner confirmation of P0057 only; no underbody heater tests.
This is the conservative boundary from the reviewed code record. This page has no frozen site-wide safety grade, so it does not publish a repair route.
What to tell the garage about P0057
Do not drive until checked. Bank 2 sensor 2's heater circuit is electrically low. The downstream heater on bank 2 has dropped voltage. Distinct from P0051 (upstream bank 2) and P0043 (bank 1 sensor 3).
Take these reviewed, code-specific details with you. They help the garage confirm the fault without turning this page into a repair procedure.
- HO2S Heater Control Circuit Low: Registration number
- HO2S Heater Control Circuit Low: Exact code P0057 and any companion codes
- HO2S Heater Control Circuit Low: Whether the engine management light is steady or flashing
- HO2S Heater Control Circuit Low: Companion P0056 or P0058 if present
What does P0057 mean?
P0057 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P00xx block, which covers fuel and air metering. The stored description is “HO2S Heater Control Circuit Low”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.
Will P0057 fail an MOT?
An illuminated engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off. P0057 does not change that lamp rule.
Before booking your test, check what usually fails on your car: see our MOT pass rates by make and model, built from 33.1 million DVSA tests.
Related guides
Related fault codes
P0057 — quick answers
Is it safe to drive with P0057?
Do not drive until checked. We have no verified driving guidance for P0057. Escalated: do not drive until that low downstream heater is checked. Stop if the lamp flashes.
Will P0057 fail my MOT?
An illuminated engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off. P0057 does not change that lamp rule.
Fault-code identifiers are standard diagnostic facts. Their explanations and diagnostic guidance on this site are original editorial summaries, not reproduced SAE wording. MOT defect rules reflect the DVSA MOT inspection manual (2026). This page is general guidance for UK drivers, not a substitute for a professional diagnosis.