P26F6Coolant Pump C Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P26F6 is stored when the control line of coolant pump C carries a higher voltage than the commanded state allows. In practice that means the wire touches a live circuit, the pump has lost its ground so the line floats up, or the line is open between driver and pump in a way the output stage reads as high. No public service document covers P26F6 itself. The low-side sister P26F5 is documented by Bentley for the auxiliary heater pump of its VW-group V8 models, where internal corrosion and pump self-diagnosis were the causes; CARB requires electric parts serving emission control or other monitors to be checked for such circuit faults. A pump held permanently on may keep running after the engine is switched off and drain the battery; one that cannot start leaves its loop without flow.
- What you may notice
- Check engine light on
- Pump runs on after switch-off or does not run at all
- Weak heater output with the engine idling
- Likely causes
- LikelyControl wire shorted to battery voltage
- PossibleMissing or corroded ground at pump C
- RareInternal electronics of the pump failed
- 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: €100 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.