P26A5
Engine Coolant Bypass Valve A Position Sensor Circuit Range/Performance
The bypass valve A position sensor reading does not correlate with commanded position. Sensor drift or worn linkage.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Sensor signal drift after thermal agingPossible
- Worn linkage between actuator and valvePossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Bypass Position Sensor A
- Actuator Linkage
P26A5 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.