MS-700.qxd
24/06/03
15:19
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Troubleshooting
This section contains a list of possible problems, as well as a list of recommended tests
to solve these problems.
The LED of the electronic module does not light up if the buttons of the operating
element are pressed.
Check the 8-pin compact connector which branches off from the electronics module and
ensure that it is connected properly to the operating element. Check the
colour coding on the connection plug of the operating element and ensure that the
terminals are inserted properly into the operating element. If they are inserted properly,
check the current supply and the earthconnection of the electronics module. The orange
cable should have a battery voltage of + 12 V when the ignition is switched on, and the
green cable should have a good earthing connection.
The LED of the electronics module does not light up if the brake is activated.
Ensure that the LED of the electronics module lights up when the buttons of the operating
elements are pressed. If it does not light up, the current supply and the earthing
connection of the electronics module must be checked. The orange cable should have a
battery voltage of + 12 V when the ignition is switched on, and the green cable should
have a good earthing connection.
Check the connection to the brake light switch using a voltmeter. The brown-white cable
from the electronics module should be connected to a brake light switch cable which is
either fed constantly or via the ignition. The brown cable should be connected to the
brake light switch cable, which connects the brake light bulb to the brake light switch.
You therefore receive an earth signal from the feed cable to the brake light bulb, if the
brake pedal is not activated and a plus signal (+ 12 V) if the brake pedal is activated. The
brown-white and the brown cable are interchangeable. Some brake light circuits have
a feedcable via ignition, therefore check the cable with the ignition switched on. For
safety reasons, cruise control does not operate if there are problems in the original brake
light circuit of the vehicle. Therefore, check the brake lights to make sure they are working
correctly.
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