Without ABS
1. Remove the vehicle speedometer sensor.
2. Measure voltage (AC range) between terminals of the vehicle speedometer sensor while the gear is turning.


3. Install the vehicle speedometer sensor.
Vehicle speedometer sensor removal/installation
Manual transaxle removal/installationMazda 6 Service Manual: Engine control system operation inspection
Main Relay Operation Inspection
Verify that the main relay clicks when the ignition switch is turned to ON
position and off.
If there is no operation sound, inspect the following.
- Main relay (See RELAY INSPECTION.)
- Harness and connector between ignition switch and main relay termi ...
Mazda 6 Service Manual: Pcv valve inspection
1. Disconnect the negative battery cable.
2. Remove the intake maniforld.(see INTAKE-AIR SYSTEM REMOVAL/INSTALLATION.)
3. Remove the PCV valve.
4. Blow through the valve and verify that air flows as specified.
If not as specified, replace the PCV valve.
Specification
...