P26BEEngine Coolant Bypass Valve D Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P26BE flags a drive circuit of valve D that reads too low, normally because the wiring or the valve itself is grounded. No manufacturer documents P26BE publicly. Ford, whose valve D is the cabin heating valve, reports only the general circuit code P26BD and, from 2024, the short-to-battery code P26BF. The closest documented logic belongs to valve C: GM's 2025 diesel table looks for grounded lines on that valve's H-bridge in each motor direction and grades it Type B. CARB requires output circuits to be monitored for circuit faults. A grounded line may keep a low-side driven valve energised or make the driver cut out. On a heater valve the result is mostly wrong cabin temperature, though a valve in the engine loop can also upset warm-up.
- What you may notice
- Check engine light
- Cabin heat stuck at full or at minimum
- Valve D does not react to commands
- Likely causes
- LikelyDrive wire shorted to ground
- PossibleInternal short in valve D
- RareMoisture or corrosion in the connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.