3233847 - E2021 BRAKE LIGHTS - Description (Sedan)

Description

The brake lights are located at the rear in the side lights and in the central third brake light and consist of 10 separate bulbs.These are operated whenever the brake pedal is pressed, by means of a switch on the pedal itself.The correct operation of the side brake lights is controlled by the check device for the exterior lights, located inside the rev counter module.

The following faults may occur:

  • blown bulb
  • bulb s.c. to earth or positive
  • incorrect bulb (5W bulb instead of 21W)
A special failure warning light, also in the rev counter module, comes on for all other faults in the various circuits. This warning light comes on for about 4 seconds when the ignition key is turned to MAR, to indicate it is working properly, then it goes off.The third centre brake light is not controlled by the check panel.The circuit is protected by the two fuses for the lights controlled by the check panel, one for the lights on the right hand side, the other for those on the left hand side and by a fuse on the supply line for all three brake lights.A braking signal is also sent from the switch to the ABS, which detects braking status and therefore introduces braking control. The same signal is also sent to some engine management systems, which take the braking condition into account when determining the engine control mode. The switch also has a 'pedal released' signal used by the ABS for the VDC  See E7022  VDC function and by the Cruise Control.