Mazda 2002 6 Workshop Manual page 369

Variable Valve Timing Control System Operation Inspection
When idling cannot be continued
1. Remove the oil control valve (OCV) and verify that the spool valve is at maximum retard position.
2. If the spool valve is stuck in advance direction, replace the oil control valve (OCV).
3. Connect the oil control valve (OCV).
4. Turn the ignition switch on.
5. Verify that the spool valve is at maximum retard position.
6. If the spool valve is stuck in advance direction, inspect for the following.
• Short circuit in harnesses or connectors between the oil control valve (OCV) and the PCM.
7. Inspect the variable valve timing actuator.
When idling can be continued
1. Warn up the engine.
2. Connect WDS or equivalent to DLC-2.
3. Idle the engine.
4. Select VT DUTY1 PID.
5. Set the oil control valve (OCV) duty valve to 100% 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 next step.
6. Remove the oil control valve (OCV) and connect the oil control valve (OCV) connector to the oil control valve
(OCV).
7. Turn ignition switch to ON.
8. Select VT DUTY1 PID.
9. Set the oil control valve (OCV) duty value to 100% and verify that the spool valve operates in the advance
direction.
10. If not as specified, inspect the following.
• Oil control valve (OCV) operation.
• Harnesses and connectors between the oil control valve (OCV) and the PCM for open or short.
11. Inspect the following hydraulic passages for clogging and/or leakage.
• Oil pressure switch—oil control valve (OCV)
• Oil control valve (OCV)—camshaft
• Camshaft internal passage
12. If they are okay, replace the intake camshaft pulley (with a built-in variable valve timing actuator).
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