1. Verify that the joint shaft is not twisted or cracked.
2. Turn the joint shaft by hand and verify that the bearing rotates smoothly and freely.

Drive shaft
Joint shaft removal/installationMazda 6 Service 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
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Mazda 6 Service Manual: Front Passenger Occupant Classification Sensor
Your vehicle is equipped with a front passenger occupant classification sensor
as a part of the supplemental restraint system. This sensor is equipped in the front
passenger's seat cushion. This sensor measures the electrostatic capacity of the
front passenger's seat. The SAS unit is designed ...