Engine Coolant Bypass Valve A Control Circuit / Open
The controller cannot drive the engine coolant bypass valve A. The valve usually routes coolant around the radiator during warm-up; without it warm-up takes longer and emissions during the warm-up phase rise.
Affected components
- Coolant bypass valve a
- Solenoid
- Wiring harness
Common causes
- High likelihood: Open coil in bypass valve solenoid
- Medium likelihood: Broken control wire
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.