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

Other materials:

Mazda 6 Service Manual: Camshaft position (cmp) sensor inspection
Caution When foreign material such as an iron chip is on the CMP sensor, it can cause abnormal output from the sensor because of flux turbulence and adversely affect the engine control. Be sure there is no foreign material on the CMP sensor when replacing. Note Perform the follow ...

Mazda 6 Service Manual: Supplier identification procedure
Note When asking the supplier (service center) for repair or replacement, verify which supplier the module belongs to and enter in the Audio Repair Order Form. Identification With Printed Numbers/Label 1. Remove the audio unit. 2. Verify the supplier name written on the label attached ...