Mazda 6 Service Manual: No.20 noise occurs at idle when vehicle is stopped in all positions/ranges

No.19 excessive shift shock on torque converter clutch (tcc)

No.21 noise occurs at idle when vehicle is stopped in d, s, l ranges, or in r position

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Mazda 6 Service Manual: Exterior lighting system
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Mazda 6 Service Manual: Engine coolant temperature (ect) sensor inspection
Note Perform the following inspection only when directed. ECT Sensor Resistance Inspection 1. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS.) 2. Remove the ECT sensor (located above the starter). 3. Place the ECT sensor in water with a thermometer, and heat the water gra ...