1. Connect the WDS or equivalent to the DLC-2.
2. Measure the PID value.
Note
PID/DATA MONITOR AND RECORD function table

Dtc p0841
TroubleshootingMazda 6 Service Manual: Lights-On Reminder
The lights-on reminder is operable when the time setting*1 of the auto headlight
off function is off.
If lights are on and the ignition is switched to ACC or off, a continuous beep
sound will be heard when the driver's door is opened.
*1 If the light switch is left on, the auto headlight off f ...
Mazda 6 Service Manual: Blind Spot Monitoring (BSM) (Some models)
The Blind Spot Monitoring (BSM) is designed to assist the driver in checking
the area to the rear of the vehicle on both sides during lane changes by notifying
the driver of the presence of vehicles approaching from the rear in an adjacent
lane.
The Blind Spot Monitoring (BSM) detects vehicle ...