| CAUTION | If ECM replacement is instructed in following tests, always ensure ECM connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction. |
Note. Variable Valve Timing (VVT) sensor may also be referred to as camshaft position sensor.
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
The Variable Valve Timing (VVT) sensor consists of a signal plate and pick-up coil. The signal plate has one tooth and is mounted on intake camshaft. The VVT sensor provides feedback to ECM in order to control intake valve timing. DTC is set when ECM does not detect a VVT sensor signal for more than 4 seconds while engine is cranking, or for 5 seconds while engine speed is more then 600 RPM. Possible causes are
- VVT sensor circuit is open or shorted.
- Defective VVT sensor.
- 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.