What it means
The rocker arm actuator A on bank 2 is commanded to engage but does not switch. Engine stays in the wrong lift mode under load on this bank.
At a glance
- Usually lights the check-engine light
How it works
Rocker arm actuator A changes valve lift on bank 2 so the engine can use the commanded lift mode. The controller sets this code when it commands the actuator to engage but does not detect the expected change, indicating a switching problem rather than simply an electrical open.
Common causes
Most likely first.
- Low oil pressure cannot move the actuator
- Mechanical lock pin stuck in unactivated position
- Carbon or debris buildup preventing free movement
Symptoms
- Check-engine light
- Reduced engine power or acceleration
- Rough running or engine misfire
How to diagnose it
- Record freeze-frame data and review live actuator command and position data to confirm when bank 2 actuator A fails to switch.
- Check engine oil level and condition first, because low or degraded oil can prevent the hydraulic mechanism from moving.
- Inspect the bank 2 actuator A connector and wiring for damage or poor contact, and check for related circuit codes.
- Test oil pressure according to the manufacturer's procedure if oil condition is acceptable but the actuator still will not engage.
- If oil pressure and the electrical circuit are satisfactory, inspect the actuator mechanism for a stuck lock pin or debris restricting movement.
Common fixes
- Correct the oil level and replace oil and filter if due or contaminated.
- Repair a loose or damaged actuator A connector or wiring on bank 2.
- Clean or replace the actuator if its spool or lock pin is sticking.
- Repair an oil-pressure problem that prevents the bank 2 mechanism from engaging.
Can I keep driving?
Avoid heavy acceleration and long trips if power is reduced or the engine runs roughly; bank 2 may not switch to the lift mode needed under load. Stop driving if misfiring becomes severe or the check-engine light flashes.
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.