OBD-II code · Powertrain (generic, extended)
P26C1 Engine Coolant Bypass Valve D Range/Performance
The fourth coolant bypass valve responds to commands but the resulting coolant temperature behaviour is not as expected.
Is it safe to drive with P26C1?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyValve partially stuck by sediment
- PossibleWeak return spring fails to close fully
- Less likelySensor element aged beyond calibration window
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Coolant Bypass Valve D, Thermostat Housing
Related codes
- P26A3Engine Coolant Bypass Valve A Range/Performance
- P26B0Engine Coolant Bypass Valve B Range/Performance
- P26BBEngine Coolant Bypass Valve C Range/Performance
- P2E66Engine Coolant Bypass Valve E Range/Performance
- P26BEEngine Coolant Bypass Valve D Control Circuit Low
- P26BFEngine Coolant Bypass Valve D Control Circuit High
- P26C0Engine Coolant Bypass Valve D Stuck/Open
- P26C2Engine Coolant Bypass Valve D Stuck Closed
- P26C3Internal Control Module Transmission Range Sensor Performance
- P26C4Internal Control Module Clutch Pedal Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.