LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2004 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 16 (Engine Control System Self-Diagnostics - V6) >> Diagnostic Tests >> DTC P1656 Or DTC P1663: Oil Control Valve Malfunction >> Circuit Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit Description

WARNING: This page is about a different car, the 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.

The Variable Valve Timing (VVT) system controls intake valve timing in response to driving conditions. Engine Control Module (ECM) controls Variable Valve Timing (VVT) Oil Control Valve (OCV) to ensure correct valve timing. VVT OCV is located is mounted on intake side of cylinder head, on flywheel side of engine. Oil pressure controlled by the VVT OCV is supplied to the VVT controller. VVT controller then changes relative position between camshaft and crankshaft. VVT controller is located on the back of intake camshaft. DTC P1656 is for bank No. 1. DTC P1663 is for bank No. 2. DTC is set if ECM detects an open or short in VVT OCV circuit. Possible causes are: