Lamp Defective message
It keeps throwing a Lamp Defective message but I'm damned if I can find a dud light. The message appears as soon as I start up. I have an iCarsoft but it doesn't work on this model so I have been unable to scan for codes to locate the supposedly faulty light.
When I first had this error I found a dud brake light bulb which fixed it but that only appeared when I touched the brakes for the first time after startup. The message is now appearing without any lights being on.
Has anybody got any ideas?
It keeps throwing a Lamp Defective message but I'm damned if I can find a dud light. The message appears as soon as I start up. I have an iCarsoft but it doesn't work on this model so I have been unable to scan for codes to locate the supposedly faulty light.
When I first had this error I found a dud brake light bulb which fixed it but that only appeared when I touched the brakes for the first time after startup. The message is now appearing without any lights being on.
Has anybody got any ideas?
Stinks, because I like the LED look in the side markers. Unsure if it applies but thought I'd throw it in there.
Stinks, because I like the LED look in the side markers. Unsure if it applies but thought I'd throw it in there.
Not fully true... Canbus LEDs won't throw error codes as they're designed to pull similar power draw as halogens, tricking the SAM to not throw codes. We have these canbus enabled LEDs if interested.
As for OP, is it giving you more information than just light out? Like which side of the tail light? If it's only a single side, try swapping bulbs left and right till the error pops up on the other side which would identify the faulty bulb.

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-Michael
Last edited by AZN Optics; Nov 5, 2019 at 06:41 PM.
As for OP, is it giving you more information than just light out? Like which side of the tail light? If it's only a single side, try swapping bulbs left and right till the error pops up on the other side which would identify the faulty bulb.
note: even the china made led bulbs (especially those off of fleabay) that CLAIM to be CANBUS compliant and seem to be bargain prices.....majority do NOT work.
Not point in wasting your time and $$ on those snake sales listings.... buy from a reliable source that backs up their LED bulbs.
Here in the US - on the front fender we have "City Lights" that often are the issue.
The discussion above - "if someone replaces with a genuine MB bulb with a LED bulb - the LED might work but still trigger the Warning"
If you pull a bulb to replace that bulb - please understand that many of the MB small bulbs have "different pin fitting" than other/generic bulb of the same size.
Also - many owner's choose to replace brake light bulks in matching left/right pairs - if one side goes replace both sides.
For example - your rear brake bulbs have "offset pins" ike 12PM/4:30M - where generic's are 12PM/6PM - often people will "jam in a generic bulb" which can work short
term but fracks up that socket.
Good luck on your search - keep the beat !
just because they're working doesn't mean the bulb should be disregarded as a potential culprit. in the case of taillights, they're notorious
for triggering bulb malfunction warning due also to their poor mount design. if this is the cause, you may need to reseat or improve
contact (decreasing resistance) between the bulb/socket and taillight housing contact panel (which functions as a circuit board)
yes, using an LED can trigger the bulb message as the interrogation system was not designed to work happily with all LED resistance designs
occasionally, the brake light switch under the dash may be the problem
more stuff to read under LIGHT - bulb malfunction
check out the PDF here
the big clue you have is that the error message activates as soon as you activate the brake so I'd focus on the rear of the vehicle first
lastly, as you probably figured out by now, "bulb malfunction" isn't always the case and should probably read "anomaly in the exterior light circuit" which is a little more vague and accurate
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Turns out it was a reversing light with a bad contact. Cleaned the base contacts and message gone.
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