Mazda MX-5 Miata Sport 2007 Manual page 2077

2007 ENGINE PERFORMANCE Symptom Troubleshooting - MX-5 Miata
If simulation function of M-MDS is used:
1. Warm up the engine to normal operating temperature.
2. Connect the M-MDS or equivalent to DLC-2.
3. Start the engine and run it at idle.
4. Select VT DUTY1 PID.
5. Increase the oil control valve (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 oil control valve (OCV) with connector is connected.
7. Turn the ignition switch to the ON position.
8. Select VT DUTY1 PID.
9. Increase the oil control valve (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-oil control valve (OCV)

Oil control valve (OCV)-camshaft

Camshaft internal passage

If not as specified, inspect the following:

Oil control valve (OCV) operation

Harness and connectors for open or short (Oil control valve (OCV)-PCM terminal 2E)

10. If they are okay, replace the intake camshaft pulley (with a built-in variable valve timing actuator).
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 oil control valve (OCV) and verify that the spool valve is at maximum retard position.
3. Connect the oil control valve (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 oil control valve (OCV) and the

PCM.
6. Inspect the variable valve timing actuator.
(See VARIABLE VALVE TIMING ACTUATOR INSPECTION [LF] .)
7. Disconnect oil control valve (OCV) connector.
2007 Mazda MX-5 Miata Sport