1. Disconnect the negative battery cable.
2. Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION)
3. Disconnect the key reminder switch connector.
4. Inspect for continuity between the key reminder switch terminals using an ohmmeter.


Key reminder switch removal/installation
Cigarette lighter removal/installationMazda 6 Service Manual: Dtc c1145, c1155, c1165, c1175
Caution
When attaching the tester lead to the DSC HU/CM connector the SST
(49 G066 004) must be used.
Diagnostic procedure
...
Mazda 6 Service Manual: Traffic Sign Recognition System (TSR) (Some models)
The Traffic Sign Recognition System (TSR) helps prevent the driver from overlooking
traffic signs, and provides support for safer driving by displaying traffic signs
on the active driving display which are recognized by the Forward Sensing Camera
(FSC) or recorded in the navigation system whil ...