OBD-II code · Powertrain (generic, extended)

P26BC Engine Coolant Bypass Valve C Stuck Closed

The third coolant bypass valve is stuck closed.

Is it safe to drive with P26BC?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyValve seized closed by debris
  • PossibleActuator linkage jammed in closed position
  • Less likelyCarbon or debris buildup preventing free movement

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2.5 h
Emissions test
Usually unaffected
Parts involved
Coolant Bypass Valve C, Thermostat Housing

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.