Code result
P26BB
Engine Coolant Bypass Valve C Range/Performance
Moderate severity
What it means
The third coolant bypass valve responds to commands but the resulting coolant temperature behaviour is not as expected.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Valve partially stuck by sediment
highOne of the most commonly reported causes for this code — check this first.
Weak return spring fails to close fully
mediumA plausible cause — test and verify before replacing parts.
Sensor element aged beyond calibration window
lowLess common, but worth ruling out after the more likely causes.
Related help
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