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: Tiedown Hooks (Some models)
CAUTION
Do not use the front and rear tiedown eyelets for towing the vehicle. They
have been designed only for securing the vehicle to a transport vessel during shipping.
Using the eyelets for any other purpose could result in the vehicle being damaged.
Tiedown Hooks
1. Remove the tiedown eye ...
Mazda 6 Service Manual: Antilock Brake System (ABS)
The ABS control unit continuously monitors the speed of each wheel. If one wheel
is about to lock up, the ABS responds by automatically releasing and reapplying
that wheel's brake.
The driver will feel a slight vibration in the brake pedal and may hear a chattering
noise from the brake system ...