P26AEEngine Coolant Bypass Valve B Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- With P26AE the valve B drive output sees voltage where it expects none, typically a short to battery. GM's 2016 Volt table again applies it to the second drive line of the one bypass valve: the VICM sets it when driver 2 flags a short to high while the valve is stopped or commanded low, after 16 failures in 20 samples at 100 ms, Type B. Ford's 2024–2025 gasoline summary lists P26AE as the short-to-battery case of the active transmission cooling valve, also filed as P26AC_12, detected when the smart driver reports a fault for 5 s. A pinched harness touching a supply wire or an internally shorted valve motor are the main causes; drivers often protect themselves by switching off, so the valve stops moving.
- What you may notice
- Check engine light
- Valve stays in its last position
- Transmission or cabin temperature control off target
- Likely causes
- LikelyDrive wire shorted to a battery-voltage wire
- PossibleInternally shorted valve motor or solenoid drawing excess current
- RareDamaged output stage in the control module
- 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: €80 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.