1. Connect the connector to the running light unit.
2. Connect the negative battery cable.
3. Measure the voltage at the running light unit using voltmeter.
4. If the value are not as specified in the Terminal Voltage List (Reference), inspect the parts under Action and related wiring harnesses.
5. If the system does not work properly even though the parts or related wiring harnesses do not have any malfunction, replace the running light unit.
Terminal Voltage List (Reference)



Running light unit removal/installationMazda 6 Service Manual: Instrument cluster input/output check mode
Note
In this mode, it is possible to check the items in the following
chart.
Diagnostic Trouble Code Chart
Note
Diagnostic trouble codes which are not listed may be indicated,
but they cannot be inspected.
The diagnostic trouble codes are displayed in numerical order.
(While ...
Mazda 6 Service Manual: Lane-Change Signals and Three-Flash Turn Signal
Lane-Change Signals
Move the lever halfway toward the direction of the lane change—until the indicator
flashes— and hold it there. It will return to the off position when released.
Three-Flash Turn Signal
After releasing the turn signal lever, the turn signal indicator flashes three
times ...