WARNING:
A hot engine can cause severe burns. Turn off the engine and wait until it is cool before servicing.
CAUTION:
Do not disassemble the hydraulic variable valve timing actuator because it is a precision unit.
1. Remove the battery cover..
2. Disconnect the negative battery cable..
3. Remove the plug hole plate..
4. Remove the ignition coil/ion sensors..
5. Remove the cylinder head cover..
6. Verify that the notch of the rotor and projection of the cover on the hydraulic variable valve timing actuator are aligned and fitted.

If the notch of the rotor and projection of the cover are not aligned, rotate the crankshaft in the direction the engine rotates two turns and verify that they are aligned.
If the notch of the rotor and projection of the cover are still not aligned, replace the hydraulic variable valve timing actuator..
If, when turning the crankshaft, there is a hitting noise from the hydraulic variable valve timing actuator each time before the cam reaches its maximum lift, it means that the actuator is not secured. Replace the hydraulic variable valve timing actuator..
7. Install in the reverse order of removal.
Variable Valve Timing Actuator Removal/Installation [Mzr 2.3 Disi Turbo]Stop Vehicle in Safe Place Immediately
If any of the following warning lights turns on, the system may have a
malfunction. Stop the
vehicle in a safe place immediately and contact an Authorized Mazda Dealer.
...
Air Intake Actuator Inspection [Full Auto Air Conditioner]
1. Connect battery positive voltage to air intake actuator terminal B (or C),
connect terminal C (or B) to ground, and then verify that the air intake actuator
operates as shown in the table.
If the operation condition is not normal, replace the air intake actuator.
...
Clutch Fluid Inspection [C66 M R]
NOTE:
A common reserve tank is used for the clutch system and brake system.
1. Verify that the clutch fluid is between the MIN mark and the MAX mark.
Verify that there is no clutch fluid leakage then add clutch fluid to the
level between the MIN mark and the MAX mark..
...