Mazda 6 Service Manual: Dtc c1955, c1956

Dtc c1953, c1954

Diagnostic procedure ...

Dtc u2021

Note To warm up the engine completely, idle the engine and wait for more than 5 minutes. Diagnostic procedure ...

Other materials:

Mazda 6 Service Manual: Intermittent concern troubleshooting
  Vibration Method 1. If malfunction occurs or becomes worse while driving on a rough road or when engine is vibrating, perform the steps below. Note There are several reasons vehicle or engine vibration could cause an electrical malfunction. Some of the things to check for are: ...

Mazda 6 Service Manual: Driving Tips
WARNING Do not let the vehicle move in a direction opposite to the direction selected by the selector lever: Do not let the vehicle move backward with the selector lever in a forward position, or do not let the vehicle move forward with the selector lever in the reverse position. Otherwise, t ...