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: General procedures
PRECAUTION (SUSPENSION)
Wheels and Tires Removal/Installation
When a wheel is installed, tighten it to 88-118 N·m {9.0-12.0 kgf·m,
65.0-87.0 ft·lbf}.
Suspension Links Removal/Installation
Tighten any part of the suspension that uses rubber bushings only after the
vehicle has been lowered ...
Mazda 6 Service Manual: Engine removal/installation
Warning
Fuel vapor is hazardous. It can very easily ignite, causing
serious injury and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injures or death and damage. Fuel can also irritate skin and
eyes. ...