Mazda 6 Service Manual: No.9 abnormal shifting

No.8 does not shift to fourth gear (4gr)

No.10 frequent shifting

Other materials:

Mazda 6 Service Manual: Generator removal/installation
Warning When the battery cables are connected, touching the vehicle body with generator terminal B will generate sparks. This can cause personal injury, fire, and damage to the electrical components. Always disconnect the battery negative cables before performing the following operation. ...

Mazda 6 Service Manual: Contact Authorized Mazda Dealer and Have Vehicle Inspected
If any of the following warning lights or the indicator light turns on/flashes, the system may have a malfunction. Contact an Authorized Mazda Dealer to have your vehicle inspected. ...