Question

For engine code P0012, what part do I need to buy, and where is located for 2005 Scion xA?

Answer 1

P0012 Scion - Camshaft Position 'A' Timing Over-Retarded Bank 1

The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to regulate the intake camshaft angle. As a result of the angle change, the engine timing is advance or retard. Optimizing engine timing will help the engine improve torque and fuel economy, and the exhaust emissions decrease under overall driving conditions. The Variable Valve Timing (VVT) system includes the Oil Control Valve (OCV) and VVT controller. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control
 

When was the last time you replaced your oil? If you have not replaced it in the 4k miles replace the oil first. 

Possible causes:
- Dirty or low engine oil
- Faulty variable valve timing (VVT)
- Faulty oil control valve (OCV)
- Variable Valve Timing (VVT) harness is open or shorted
- Oil Control Valve (OCV) harness circuit is open or shorted
- Damaged ECM

Answer 2

P0012 Scion Code - Camshaft Position 'A' Timing Over-Retarded Bank 1
Read more: https://www.autocodes.com/p0012_scion.html