This is maintenance mode indication.
The purpose of Maintenance mode are:
Inspection of ignition timing etc. when performing engine maintenance, idle speed exhaust emissions testing (CO, HC), etc.
Tests using a speedometer tester, two-wheel chassis dynamometer, etc.
It keeps the engine idling when park (P) is selected and also cancels traction control.
Test items in Maintenance mode depending on [Shift State] are:
Vehicle straight travelling test (side slip inspection) - [D]
Braking force test - [N]
Speedometer test - [D]
Exhaust gas test (idling) - [P]
Headlight test - [P]
