What it means
The controller cannot drive the rocker arm switching actuator B on bank 1. The second valve lift mode cannot be commanded.
At a glance
- Usually lights the check-engine light
How it works
The B rocker arm actuator on bank 1 is the electrically controlled part that switches the bank’s valve mechanism into its alternate lift mode. This code sets when the controller detects an open control circuit and cannot drive actuator B, so the commanded mode may not engage.
Common causes
Most likely first.
- Open coil in oil control valve
- Broken control wire
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Rough running or engine misfire
How to diagnose it
- Save freeze-frame data and check live data for the bank 1 B actuator command and any available response or status.
- Inspect the B actuator connector on bank 1 for a disconnected plug, damaged wiring, corrosion, or loose terminals.
- Check the actuator coil and its wiring for an open circuit using the wiring diagram and manufacturer’s specification.
- With the circuit connected as specified, use a scan tool to command actuator B and check whether the controller output and actuator response are present.
- If the wiring is intact but the coil is open, replace the bank 1 B oil control valve or actuator as specified for the vehicle.
Common fixes
- Reconnect and secure the bank 1 B actuator connector.
- Repair a broken or open control wire to the bank 1 B actuator.
- Replace damaged connector terminals that interrupt the control circuit.
- Replace the bank 1 B actuator or oil control valve if its coil is open.
Can I keep driving?
If the engine runs smoothly, a short, gentle trip may be possible, but reduced acceleration can make busy traffic risky. Avoid heavy loads and stop if rough running or power loss becomes severe.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.