L3
1. Disconnect the negative battery cable.
2. Remove the plug hole plate.
3. Remove the high-tension lead. (See HIGH-TENSION LEAD REMOVAL/INSTALLATION.)
4. Remove the oil control valve (OCV) connector.
5. Remove the ventilation hose.
6. Remove the cylinder head cover. (See Cylinder Head Cover Installation Note.)
7. Remove in the order indicated in the table.
8. Install in the reverse order of removal.


Oil control valve (ocv) inspectionMazda 6 Service Manual: System wiring diagram
ABS (ABS/TCS)
DSC
FOREWORD
Before performing the steps in Symptom Troubleshooting, perform the
On-board Diagnostic Inspection. To check the DTC, follow the DTC Inspection
steps.
...
Mazda 6 Service Manual: Drive belt auto tensioner inspection
1. Remove the drive belt. (See DRIVE BELT REPLACEMENT.)
2. Verify that the drive belt auto tensioner moves smoothly in the
operational direction.
Replace the drive belt auto tensioner if necessary.
3. Turn the drive belt auto tensioner pulley by hand and verify that it
rotates smoothly ...