P26BDEngine Coolant Bypass Valve D Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P26BD is the open-load or general circuit fault on the output that drives coolant bypass valve D. Ford is the documented user. Both editions of its gasoline OBD summary, 2020–2023 and 2024–2025, assign valve D to cabin heating, meaning the valve that routes engine coolant to the heater core, and set P26BD once the PCM's smart driver signals an output fault during continuous 5 s monitoring; the 2024 edition adds the extended form P26BD_13. Ford's 2014 code list for spark-ignition engines already names P26BD with the Circuit/Open wording. GM's public tables do not use P26BD. Because the valve mainly serves the heater, the usual effect is too little or uncontrolled cabin heat rather than an engine problem. P26BE and P26BF cover shorted lines.
- What you may notice
- Check engine light
- Weak or no cabin heat
- Heater output that cannot be regulated
- Likely causes
- LikelyOpen coil or motor winding in valve D
- PossibleLoose or corroded valve connector
- PossibleBroken drive wire between PCM and valve
- 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.