P2680Coolant Degassing Valve Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2680 is the high-voltage fault of the degassing valve drive: the controller cannot pull the line down, so the valve stays in its unpowered state whatever is commanded. A wire touching a battery feed, an internally open solenoid, or a defective output transistor are the classic reasons. Because degassing only works when bubbles can reach the expansion tank, where the coolant calms and releases trapped gas, a valve stuck in the wrong state may leave air in the engine circuit or slow warm-up, depending on its default. No manufacturer documents P2680 publicly, and no threshold is published. The monitoring duty comes from CARB's comprehensive component rules. Check the coolant level and look for overheating signs.
- What you may notice
- Check engine light or stored code
- Air pockets, gurgling or weak cabin heat
- Temperature gauge higher than usual
- Likely causes
- LikelyControl wire shorted to a battery feed
- PossibleInternally open solenoid of the degassing valve
- RareDefective 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 · Often possible to do yourself.Typical cost: €40 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.