1. Inspect for continuity between the audio amplifier connector terminals and woofer connector terminals using an ohmmeter.


2. Verify that there is battery positive voltage at the woofer connector terminal A (4SD) or C (5HB) using a voltmeter.
3. Inspect continuity between the woofer connector terminal B and body ground using an ohmmeter.
Woofer removal/installation
Noise filter removal/installationMazda 6 Service Manual: Immobilizer System
The immobilizer system allows the engine to start only with a key the system
recognizes.
If someone attempts to start the engine with an unrecognized key, the engine
will not start, thereby helping to prevent vehicle theft.
If you have a problem with the immobilizer system or the key, consult ...
Mazda 6 Service Manual: Procedures for determining the location of a malfunction
System Wiring Diadram
PCM
1. Check the display of DTC U0121 and/or U0155, using the SST (WDS or
equivalent). (See DTC TABLE.)
2. Referring to the following table, determine the malfunctioning part of the
CAN system.
ABS/TCS HU/CM or DSC HU/CM
1. Accec and monitor the PCM MSG and IC MSGo ...