Continuously pressing the push button start or quickly pressing it any number of times while the engine is running or the vehicle is being driven will turn the engine off immediately. The ignition switches to ACC.
Mazda 6 Owners Manual: Dual proportioning valve inspection (without abs)
1. Connect the SSTs to the brake pipes as shown in the figure.
2. Bleed the air from the brake system.
3. Measure the fluid pressure of the master cylinder and the rear brake.
If not within the specification, replace the dual proportioning valve.
Fluid pressure
...
Mazda 6 Owners 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 ...