blue wire

[abby1]

hi guys
what does the blue wire do that runs from alternator to engine control module as my one carries a 12 volt current
still got 3 warning lights abs esp suspension 2002 allroad auto diesel
any ideas

[amiram]

The engine control module Controls the amount of the charge, 14.2 Volts in the first hour of the trip and then 13.8 volts. With regard to the 3 warning lights There may be a problem in the ABS sensor in one of the wheels.Check out fault codes it will give you an answer instead of guessing