P26A3 — standardised OBD-II powertrain code

P26A3 is a standardised (ISO/SAE) powertrain code, so it means the same thing on any vehicle — but we have not yet written a plain-English definition for this one. Below are the vehicles and failure patterns where owners report it, drawn from NHTSA complaints.

Ask A Mechanic

In our record, P26A3 is reported only on Subaru vehicles , against powertrain and engine failure patterns , across 2019–2021 model years.

In ProblemsByVin's analysis of the NHTSA owner-complaint record, owners cite P26A3 across 5 vehicle failure patterns. Diagnostic codes in complaints are reported by owners and are unverified — they point to where this code shows up, not a confirmed diagnosis. Open a page below for the full pattern (symptoms, mileage, repair costs owners cite).

Vehicles where owners report P26A3 5 patterns

2021 Subaru Crosstrek

powertrain — Thermo Control Valve (TCV) Failure with Check Engine Light

2020 Subaru Forester

powertrain — Thermo Control Valve (TCV) / Engine Coolant Bypass Valve Failure

2020 Subaru Forester

engine — Thermo Control Valve (Engine Coolant Bypass Valve) Failure

2019 Subaru Forester

engine — Thermo Control Valve (TCV) / Engine Coolant Bypass Valve Failure

2019 Subaru Forester

powertrain — Thermal Control Valve Assembly (TCVA) / Engine Coolant Bypass Valve

Codes are pulled from what owners wrote in their NHTSA filings — they're allegations, not a shop diagnosis. Always confirm with a live scan. Browse all diagnostic codes →