Engine Coolant Bypass Valve D Stuck/Open
The fourth coolant bypass valve is stuck open.
Affected components
- Coolant bypass valve d
- 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.