Mazda 6 Service Manual: No.27 constant voltage

No.26 exhaust sulphur smell

No.28 spark plug condition

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: High Beam Control System (HBC) (Some models)
The High Beam Control System (HBC) determines the conditions in front of the vehicle using the Forward Sensing Camera (FSC) while driving in darkness to automatically switch the headlights between high and low beams. Refer to Warning/Indicator Lights. While driving the vehicle at a speed of ab ...