"B" Rocker Arm Actuator Control Circuit Low (Bank 1)

Possible causes

• CommonLow, dirty or wrong-viscosity engine oil
• CommonFailed rocker arm actuator solenoid
• CommonOil control valve blocked with debris
• CommonCorroded or oil-contaminated connector
• CommonWiring damage in the valve cover harness
• PossibleFailed or collapsed switching rocker arm
• PossibleLow oil pressure from a worn pump or clogged pickup

What you might notice

• Misfire or rough running
• Ticking or tapping from the top of the engine
• Loss of power at one end of the rev range
• Worse fuel economy
• Check engine light on

What to check, in order

1. Check the engine oil level, condition and viscosity first. These actuators are driven by oil pressure through small solenoid valves, so oil that is low, degraded or the wrong grade causes more faults here than wiring ever does.
2. Ask when the oil was last changed. Extended or missed oil changes are the biggest single cause of failures in oil-actuated valve systems.
3. Listen for a tick from the top of the engine, which points at the rocker mechanism rather than the solenoid.
4. Inspect the connector for oil contamination and corrosion.
5. Measure the solenoid winding resistance against specification.
6. Read all codes - misfire codes alongside these identify which cylinders are affected.