Vehicles have various electrical parts. To protect the parts from excessive current generated when welding, be sure to perform the following procedure.
1. Turn the ignition switch to the LOCK position.
2. Disconnect the battery cables.

3. Securely connect the welding machine to the ground near the welding area.
4. Cover the peripheral parts of the welding area to protect them from weld spatter.

Electrical troubleshooting tools
Jacking positions ,vehicle lift (2 supports),safety stands (rigid rack)
positionsMazda 6 Service Manual: Intermittent concern troubleshooting
Vibration Method
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 why vehicle or engine vibration could
cause an electrical malfunction. Some of the things to check for:
- ...
Mazda 6 Service Manual: Multiplex communication system
Outline
In case the controller area network (CAN) system is malfunctioning, read
the DTCs of the following modules, using the SST (WDS or equivalent) to
determine the malfunctioning system.
- PCM
- DSC HU/CM (with DSC)
- ABS (ABS/TCS) HU/CM (with ABS (ABS/TCS)
- Instrument clus ...