1. Remove the TCS OFF switch.
2. Inspect for continuity between the TCS OFF switch terminals using an ohmmeter.
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: Abs (abs/tcs) hu/cm inspection
1. Disconnect the negative battery cable.
2. Connect the SST between the ABS (ABS/TCS) HU/CM and harness
connector with the ignition switch off.
3. Attach the tester leads to the SST and inspect voltage referring
the table below.
Terminal Voltage Table (Reference)
(Engine is idling, and co ...