"Jim GM4DHJ ..." wrote in message
...
lost a dippd beam bulb the other day .....only knew by the reflection from
the car in front....I thought canbus was supposed to warn you of
this....or is it just another digital thing that doesn't work properly ?
.....

canbus is just a communication link

it can't, on its own, tell you that the bulb doesn't work. There has to be
some logic in the bulb holder to generate and send the message (and some
logic in the central console to display the information to you)

Unsurprisingly, some manufacturers use these "features" as a way of
providing "value" in their vehicles, and some don't

tim