1. Disconnect the negative battery cable.
2. Remove the glove compartment.
3. Remove the car navigation unit. (See CAR-NAVIGATION UNIT REMOVAL/INSTALLATION.)
4. Remove in the order indicated in the table.
5. Install in the reverse order of removal.
Mazda 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: Cruise Control Function
While this function is operating, the headway control operation is canceled and
only the cruise control function operates.
The vehicle speed can be set more than about 25 km/h (16 mph).
Use the cruise control function on expressways and other highways which do not
require a lot of repeated acc ...