Circuit Description
WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Variable Valve Timing (VVT) sensor is also known as camshaft position sensor.
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. An OCV is located in each cylinder head at flywheel end of engine. Oil pressure controlled by OCV is supplied to VVT controller. VVT controller then changes relative position between camshaft and crankshaft. VVT controller is located on front of each intake camshaft. DTC P1656 or P1663 is set if ECM detects an open or short in OCV circuit. DTC P1656 is for bank No. 1 (left cylinder head) OCV circuit. DTC P1663 is for bank No. 2 (right cylinder head) OCV circuit. Possible causes are:
- Open or short in OCV circuit.
- Faulty OCV.
- Faulty ECM.