Variable Valve Timing Control System Operation Inspection

If simulation function of M-MDS is used: 

1. Warm up the engine to normal operating temperature.
2. Connect the M-MDS to the DLC-2.
3. Start the engine and run it at idle.
4. Select the VT DUTY1 PID.
5. Increase the OCV duty value and verify that the engine idles roughly or stalls.
   • If as specified, inspect the timing belt component (valve timing deviation).
   • If not as specified, go to the next step.
6. Remove the OCV with connector is connected.
7. Turn the ignition switch to the ON position.
8. Select the VT DUTY1 PID.
9. Increase the OCV duty value and verify that the spool valve operates in the advance direction.
   • If as specified, inspect the following hydraulic passage for clogging and/or leakage:
     • Oil pressure switch-OCV
     • OCV-camshaft
     • Camshaft internal passage
   • If not as specified, inspect the following:
     • OCV operation
     • Harness and connectors for open or short (OCV-PCM terminal 2E)
10. If they are okay, replace the intake camshaft pulley (with a built-in variable valve timing actuator). (See VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [LF] ).

If simulation function of M-MDS is not used: 

1. Start the engine and run it at idle.
   • If idling cannot be continued, go to Step 2.
   • If idling can be continued, go to Step  7.
2. Remove the OCV and verify that the spool valve is at maximum retard position.
3. Connect the OCV.
4. Turn the ignition switch to the ON position.
5. Verify that the spool valve is at maximum retard position.
   • If the spool valve is stuck in the advance direction, inspect for the following:
     • Short circuit in wiring harnesses or connectors between the OCV and the PCM
6. Inspect the variable valve timing actuator. (See VARIABLE VALVE TIMING ACTUATOR INSPECTION [LF]
7. Disconnect OCV connector.
8. Warm up the engine and idle it.
9. Apply battery voltage to the OCV and verify that the engine idles roughly or stalls.
   • If the engine idles roughly or stalls, inspect the timing belt component (valve timing deviation).
   • If the engine does not idle roughly or stalls, go to the next step.
10. Remove the OCV and perform spool valve operation inspection. (See OIL CONTROL VALVE (OCV) INSPECTION [LF] ).
    • If not as specified, inspect the following:
      • OCV
      • Harnesses and connectors between OCV and PCM open or short
    • If as specified, inspect the following hydraulic passages for clogging or leakage or both:
      • Oil pressure switch-OCV
      • OCV-camshaft
      • Camshaft internal passage
11. If they are normal, replace the camshaft pulley (with built-in variable valve timing actuator). (See VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION [LF] ).