Circuit Description

The Variable Valve Timing (VVT) system controls intake valve timing in response to driving conditions. Electronic Control Module (ECM) controls Oil Control Valve (OCV) to ensure correct valve timing. DTC P1656 or P1663 is set if ECM detects an open or short in OCV circuit. DTC P1656 is for bank No. 1 (right cylinder head) OCV circuit. DTC P1663 is for bank No. 2 (left cylinder head) OCV circuit. Possible causes are:

• Open or short in OCV circuit.
• Faulty OCV.
• Faulty ECM.