Bulb failure?
 

Hi,
Whilst driving during the day yesterday, my bulb light on the dash board illuminated. I was not using any of my exterior lights at the time.
I’ve tried today and it still stays on when driving. All my exterior bulbs seem OK.

Is it an interior bulb failure, or something else?

Thanks

Amo
S280 1998 W140

You need to check everwhere......sometimes tricky.

When my warning light came on....all the bulbs seemed OK.....it turned out to be 1 of the 2 license plate bulbs.

The system only monitors exterior bulbs.

The light comes on only after the affected bulb is energized. Knowing this you can narrow down the search. For example, if the light only comes on after you use your brakes for the first time, the bad bulb is a brake light. Same thing with turn signals, headlights, etc.

Bulb Out
 

The system monitors many bulbs, if it came on dring daytime check things like brake, turn indicator, etc. I have also heard of corroded sockets, or wrong wattage bulbs. I think it uses resistance or current to trigger. That is why you just cant replace bulbs with the LED or other indicators.

...sometimes, the light will come on...and you do not see any apparent problems with any bulbs...but a few days later...one bulb will start to work intermittently, and then die out completely...this has happened with me several times...ou just have to be patient...