P0021
"A" Camshaft Position - Timing Over-Advanced (Bank 2)
The bank 2 intake camshaft is more advanced than commanded, or the actuator does not respond as expected. Often caused by stuck-open oil control valves, sludge in VVT passages, or low oil pressure.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Common causes
Ordered by how often each turns out to be the cause.
- Oil control valve stuck (advance)Common
- Sludge in VVT passagesPossible
Parts involved
- Camshaft Position Actuator
- Oil Control Valve
P0021 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.