P26A3Engine Coolant Bypass Valve A Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P26A3 is a functional fault: the electrics of bypass valve A look fine, but the valve does not reach or report the position it should. GM's 2011 Volt table sets it, Type B, when the end-position learn fails with coolant above 50 °C, or when the valve has not arrived at its commanded position within 15 s. Honda calls the part an electric water valve: on the 2014 Accord Plug-In Hybrid, bulletin 20-033 blames climate control software that drove the three-way valve wrongly and replaces that unit; on the 2018 Clarity Plug-In Hybrid, 18-090 is an emissions recall with new engine software. Ram 1500 3.6 L trucks show it after a cracked valve gear or, per 07-007-24, contamination by stop-leak pellets requiring a flush.
- What you may notice
- Check engine light on
- Weak or delayed cabin heat
- Unusual coolant or transmission temperatures
- Likely causes
- LikelyBroken gear or jammed rotor inside the bypass valve
- PossibleContaminated coolant, e.g. stop-leak additives, blocking the valve
- PossibleEngine or climate control software commanding the valve incorrectly
- RareEnd-position learn not completed after replacement
- 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: €0 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.