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: Special tools
ENGINE
Ford SST numbers are collated with Mazda SST numbers in the example below.
Ford SSTs are marked with Ford SST number.
Example
1: Mazda SST number
2: Ford SST number
LUBRICATION SYSTEM
COOLING SYSTEM
FUEL AND EMISSION CONTROL SYSTEMS
CLUTCH
MANUAL TRANSAXLE
AUTOMATIC T ...
Mazda 6 Service Manual: Dtc c1955, c1956
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...