Engine Coolant Bypass Valve D Control Circuit Driver Current/Temperature Too High
The output driver for the engine coolant bypass valve D actuator reports current or junction temperature above its protection threshold. Stalled actuator or short to ground.
Affected components
- Engine coolant bypass valve d
- Ecm
Common causes
- High likelihood: Bypass actuator mechanically jammed
- Medium likelihood: Control wire shorted to ground
Possible symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Diagnostic notes
- The malfunction indicator lamp may illuminate
- Reduced-power or limp mode may occur
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.