Mazda 6 Service Manual: No.7 slow return to idle

No.6 cranks normally but will not start

No.8 engine runs rough/rolling idle

Other materials:

Mazda 6 Service Manual: To Resume Cruising Speed at More Than 25 km/h (16 mph)
If some other method besides the OFF/ CANCEL switch was used to cancel cruising speed (such as applying the brake pedal) and the system is still activated, the most recent set speed will automatically resume when the RESUME/ switch is pressed. If vehicle speed is below 25 km/h (16 mph), incre ...

Mazda 6 Service Manual: STEP 1: Contact Your Mazda Dealer
Discuss the matter with an Authorized Mazda Dealer. This is the quickest and best way to address the issue. If your concern has not been resolved by the CUSTOMER RELATIONS, SALES, SERVICE, or PARTS MANAGER, then please contact the GENERAL MANAGER of the dealership or the OWNER. If it b ...