| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION. |
Circuit Description
The Variable Valve Timing (VVT) system controls intake valve timing in response to driving conditions. ECM uses input from Crankshaft Position (CKP) sensor and Camshaft Position (CMP) sensor to control Oil Control Valve (OCV). OCV varies oil pressure between 2 circuits, changing intake camshaft position as much as 60 degrees of crankshaft angle.
DTC P1349 is set when valve timing does not change or is fixed continuously after engine is warmed up and engine speed is 400-4000 RPM. Possible causes are
- Incorrect valve timing.
- Faulty oil control valve.
- Faulty VVT controller assembly.
- Faulty ECM.
Diagnostic Aids
Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.