Home/Lexus/GS/Lexus GS II (1997-2000)/Repair manual/Testing & Diagnostics/DTC P1349: VARIABLE VALVE TIMING (VVT) SYSTEM MALFUNCTION
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DTC P1349: VARIABLE VALVE TIMING (VVT) SYSTEM MALFUNCTION Lexus GS II

CAUTIONIf 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.

Circuit Description

The Variable Valve Timing (VVT) system controls the intake valve timing in response to driving conditions. ECM uses impute from Crankshaft Position (CKP) sensor and Camshaft Position (CMP) to control the 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

  1. Valve timing.
  2. Oil control valve.
  3. VVT controller assembly.
  4. ECM.