P26A7Engine Coolant Bypass Valve A Position Sensor Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- The counterpart to P26A6: the feedback from valve A reads too high. GM's 2016 Volt table counts both a signal above its window and a broken signal circuit here, because an interrupted wire lets the input float toward the reference. The limit is 95 % of the reference (4.75 V), checked as 40 failures in 50 samples at 100 ms, Type B. The 2011 Volt table uses the same 95 % rule but prints the voltage as 4.25 V. Subaru's correction bulletin 09-132-25 also covers P26A7 for its boxer engines and again drops the first step of the published test. Subaru's earlier bulletin 09-80-21 replaced the thermo control valve with a better sealed sensor section. Check for a broken signal or ground wire and for a short to the 5 V supply before condemning the valve.
- What you may notice
- Check engine light
- Scan tool shows valve position at maximum
- Engine slow to reach operating temperature
- Likely causes
- LikelyOpen feedback or sensor ground wire
- PossibleFeedback wire shorted to 5 V reference or battery voltage
- PossibleDefective sensor in the valve housing
- 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 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.