Diagnostic procedure
Mazda 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: Woofer inspection
1. Inspect for continuity between the audio amplifier connector terminals and
woofer connector terminals using an ohmmeter.
If not as specified, replace the related wiring harnesses.
2. Verify that there is battery positive voltage at the woofer connector
terminal A (4SD) or C (5HB) u ...