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: Multi-Information Display and INFO Switch (Some models)
The multi-information display indicates the following information.
Odometer
Trip meter
Engine coolant temperature gauge
Fuel gauge
Outside temperature
Distance-to-empty
Average fuel economy
Current fuel economy
Maintenance Monitor
...
Mazda 6 Service Manual: Side air bag sensor removal/installation
Warning
Handling the side air bag sensor improperly can accidentally
deploy the side air bag module, which may seriously injure you. Read AIR BAG
SYSTEM SERVICE WARNINGS before handling the side air bag sensor. (See
SERVICE WARNINGS.)
1. Turn the ignition switch to LOCK position.
2. ...