| WARNING | Read service precautions before proceeding with service procedure. See SERVICE PRECAUTIONS . |
| CAUTION | If Engine Control Module (ECM) replacement is instructed in following test, always ensure ECM electrical connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Circuit Description
The Variable Valve Timing (VVT) system controls intake valve timing in response to driving conditions. ECM controls Variable Valve Timing (VVT) Oil Control Valve (OCV) to ensure correct intake valve timing. Engine oil pressure which is controlled by VVT OCV is supplied to VVT controller on front of intake camshaft. VVT controller changes relative position between camshaft and crankshaft. VVT OCV may also be referred to as VVT camshaft timing oil control valve. DTC is set if ECM detects an open or short in VVT OCV circuit. Possible causes are
- VVT OCV circuit is open or shorted.
- Defective VVT OCV.
- Defective ECM.
Diagnostic Aids
Using Toyota hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.