What it means
Voltage on the rocker arm actuator B control line on bank 1 is above the expected window. Typical causes are a short to battery or an open solenoid coil.
At a glance
- Usually lights the check-engine light
How it works
The B rocker arm actuator control circuit on bank 1 carries the controller’s command to switch the valve mechanism’s lift mode. This code sets when circuit voltage is above its expected range, which can happen if the control wire is shorted to battery voltage or the actuator coil is open.
Common causes
Most likely first.
- Control wire shorted to B+
- Open solenoid coil
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Rough running or engine misfire
How to diagnose it
- Record freeze-frame data and check whether the bank 1 B circuit fault occurs when the actuator is commanded on or off.
- Inspect the B actuator connector and harness on bank 1 for an open wire, loose terminal, chafing, or contact with a battery supply wire.
- Check the actuator coil for an open circuit and inspect connector pins for corrosion or poor contact.
- Using the wiring diagram, test the control wire for a short to battery voltage and verify continuity against the manufacturer’s specification.
- If the wiring is intact, check controller output as specified and replace the bank 1 B actuator if its coil is open.
Common fixes
- Repair an open bank 1 B actuator control wire.
- Repair a short between the bank 1 B control wire and battery supply.
- Clean or replace connector terminals that interrupt the circuit.
- Replace the bank 1 B actuator if its solenoid coil is open.
Can I keep driving?
A short, gentle trip may be possible if the engine runs smoothly, but reduced power or rough running can make acceleration unpredictable. Avoid heavy loads and stop if the engine misfires or power drops sharply.
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.