184001928 - E2021 BRAKE LIGHTS - DESCRIPTION

Description

The brake lights are located at the rear in the side lights and in the central third brake light and consist of 5 separate bulbs.These are operated whenever the brake pedal is pressed, by means of a switch on the pedal itself.
the switch fitted on the pedal assembly consists of two contacts which supply two signals: the first which is the ''N.A.'' type recognizes the position of the brake pedal when it differs from the rest position, i.e. pedal pressed; the second, which is the ''N.C.'' type, recognizes the brake pedal in the rest position.
The lights are switched on by the N.A. contact (pedal pressed). The ''N.A.'' switch information is sent, in particular to the engine management control unit and the ABS control unit.    See E5030 PETROL ENGINE ELECTRONIC MANAGEMENT,    See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT,    See E7020 ABS.The control function is activated by the go ahead signals from the key in the ON position (INT) and the contact for the above mentioned switch.

The correct operation of the side lights is controlled by the brake lights ''check'' function: the following are checked:

  • 0pen circuit (bulb missing or wiring broken)
  • short circuit to earth (bulb short circuit or wiring short circuit to earth)
  • short circuit to Vbatt (wiring short circuit to Vbatt)
The continuity of the fuse protecting the switch on the brake pedal is also checked.If one of the situations described above is detected, the Body Computer notifies the CAN of the failure state: the special ''lights failure'' warning light in the instrument panel comes on and, at the same time, the information is shown on the display.
the centre third brake light is operated directly by the switch on the pedal and is not subjected to a check.