The MY20 Service Manual indeed addresses manual gearboxes, as it references "Neutral."
Initiation...
CAUTIONS: The electric park brake (EPB) switch's apply/release function is disabled in this mode (to ensure technician safety), thus do not operate the vehicle under these conditions. Noncompliance with this directive may result in personal injury.
This process necessitates that the car is in either the Park or Neutral position, the ignition is activated (the engine must be off), and the parking brake system is disengaged.
Upon installation of the rear brake pads or brake discs, the Service Mode must be deactivated.
This process facilitates the release of the parking brake during the removal and installation of replacement rear brake pads or brake discs.
1. Depress and maintain the parking brake switch in the disengaged position.
2. Pause for one second.
3. Depress and maintain the accelerator pedal in the fully open throttle position.
4. Wait one second.
5. Turn the ignition OFF and then ON immediately.
NOTE: An audible signal will indicate that the parking brake has been disengaged in Service Mode.
6. Depress the accelerator pedal and return the parking brake switch to the neutral position.
Disengagement...
WARNING: This method necessitates that the car is in either Park or Neutral, with the ignition activated (the engine must be off) and the parking brake system set to Service Mode.
1. Press and hold the parking brake switch in the apply position.
2. Pause for one second.
3. Depress and maintain the accelerator pedal in the fully open throttle position.
4. Pause for one second.
5. Turn the ignition OFF and then ON immediately.
NOTE: An audible signal will indicate that the parking brake has been disengaged from Service Mode.
6. Depress the accelerator pedal and return the parking brake switch to the neutral position.