The camshaft that usually runs the intake valves on the second side of the engine is opening them earlier than the computer asked. Bank 2 is the side without cylinder 1.
Check the oil level with the dipstick. Low or very old oil is a common cause, and an oil change sometimes clears it.
We rate P0021 as Get it checked this week. It is not an emergency yet, but it can get worse. If the light starts flashing, stop driving soon.
Intake camshaft timing is too far ahead (bank 2). The camshaft that usually runs the intake valves on the second side of the engine is opening them earlier than the computer asked. Bank 2 is the side without cylinder 1.
We rate P0021 as Get it checked this week. It is not an emergency yet, but it can get worse. If the light starts flashing, stop driving soon.
The most common causes, in order: Low, dirty or wrong oil, because the timing adjuster runs on engine oil; A stuck or dirty oil control valve, the small part that sends oil to the timing adjuster; A worn or stretched timing chain; A worn timing adjuster, also called a cam phaser.
Estimates only. A mechanic should confirm. The same code can mean slightly different things on different cars; the app explains it for your exact year, make, model and mileage.