Engine Coolant Bypass Valve A Control Circuit High
Voltage on the coolant bypass valve A control line is above the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Affected components
- Coolant bypass valve a
- Solenoid
- Wiring harness
Common causes
- High likelihood: Control wire shorted to B+
- Medium likelihood: Open solenoid coil
- Low likelihood: Connector pins corroded - high contact resistance
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.