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: On-board diagnostic test
DTCs Reading Procedure 1. Perform the necessary vehicle preparation and visual inspection. 2. Connect WDS or equivalent to the vehicle DLC-2 16-pin connector located as shown in the figure. 3. Retrieve DTCs by WDS or equivalent. Pending Trouble Code Access Procedure 1. Perform the necessary ...

Mazda 6 Service Manual: Foreword
Caution When the engine does not start or stalls and the following DTCs are not indicated, go to engine symptom troubleshooting. Note When the immobilizer system is defective, the engine cannot be started. If engine condition is normal but light stays on, inspect for short circ ...