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.