The meaning of the C1204 Code is necessary to know but do not use the general meaning of the code. The automobile dictionary meaning does not help you for solving the car engine problem. The engine structure in conjunction with powertrain control module (PCM) or the engine control module (ECM), triggers the C1206 code solenoid valve to control oil compression to the engine device that is connected in the valve scheme to switch valve timing between Low and High. If the engine solenoid valve has an open or short circuit, a DTC is stored. After solving the car engine, take the car for a test drive.