Engine Coolant Bypass Valve B Stuck/Open
The second coolant bypass valve is stuck in the open position. Coolant always bypasses the second radiator path.
Affected components
- Coolant bypass valve b
- Thermostat housing
Common causes
- High likelihood: Valve seized open by sediment
- Medium likelihood: Broken return spring
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.