Brake Lights

BRAKE LIGHTS - DESCRIPTION 

The vehicle brake lights are located at the rear in the side light clusters and in the special center third brake light.

The side brake lights are located in the rear side light clusters and consist of LED circuits, as the central third brake light.

The brake lights are operated each time the brake pedal is pressed via the special switch on the pedal.

The switch fitted on the pedal unit consists of two contacts which supply two signals: the first is the "Normally Open" type, which recognizes the position of the brake pedal if it is not in the rest position, i.e. the pedal is pressed; the second is the "Normally Closed" type, which recognizes the position of the brake pedal in the rest position. 

The lights are switched on by the "Normally Open" contact (pedal pressed). 

The control function is activated by the enablement signals (KEY-ON) and the command from the contact of the switch.

The brake lights check function monitors that the side lights are working correctly the following are checked:

• open circuit (bulb missing or wiring interrupted)
• short circuit to ground (bulb s.c. or wiring s.c. to ground)
• short circuit to battery voltage (wiring short circuited to Vbatt)
• The continuity of the fuse protecting the switch on the brake pedal is also checked

When one of the situations described above is verified, the Body Computer makes the failure status available to the CAN: a special lights failure warning light switches on in the instrument panel and, at the same time, the information is shown in the display by means of the specific symbol.

BRAKE LIGHTS - FUNCTIONAL DESCRIPTION 

• Switch I030 receives an ignition-operated power supply along the lines protected by fuses F37 and F51 located in the Body Computer M001.
• The "Normally Open" and the "Normally Closed" signals reach Body Computer M001 at pins 27, 34 of connector B respectively.
• The engine management control unit M010 also receives the "Normally Open" signal from the I030 switch at pin 34 of connector A.
• The Body Computer M001 controls the power supply for the rear brake lights F030 (left) and F031 (right) and the central brake light F040 from pins 51, 50 and 16 of connector C respectively.
• The Body Computer M001 - connector A - receives a direct power supply from the battery through the line protected by maxi fuse F01 of the engine compartment control unit B001.
• The Body Computer M001 receives an ignition-controlled power supply (INT) at pin 11 of connector E: this signal is used, amongst other things, to "wake up the network".
• The ground reference reaches pins 9, 10 of connector E of Body Computer M001.
• Body Computer M001 is connected via the CAN line to the instrument panel E050 to manage the "lights failure" warning light and the "brake lights check" signal if problems are detected in the circuit or in the fuse.