In certain driving conditions, the vehicle does not require the most power from the engine. In these cases, the cylinder deactivation system is generally used in vehicles with more than 8 cylinders, deactivating the corresponding cylinders to save fuel.
The cylinder deactivation system uses the variable valve timing solenoids to close the intake and exhaust valves of the deactivated cylinders. This allows cylinder gases to be trapped and reduces vibration for proper cylinder operation. The compressed exhaust gases also drive the piston backward to achieve a higher degree of overall engine balance.
The P3497 OBD2 fault code setting occurs when the Powertrain Control Module (PCM) fails to activate the cylinder deactivation system for bank 2.