Brake Light Problem 2001 CLK430
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2001 CLK430
Brake Light Problem 2001 CLK430
Every time I start up my car and press the brake I get an error message about a light malfunction. All the lights seem to be working fine. I ordered and installed new bulbs for my brake lights (WAGNER BP17881 Taillight/ taillight Bulb), but I still get the same error. I noticed that the driver-side brake light bulb is illuminating a different filament than the passenger-side one (the passenger-side seems to be brighter). Is this normal in a dual filament bulb? Does this mean that the board itself has an issue? Any suggestions on what to do next?
First picture is Driver Side Brake Light
Second Pic is Passenger Side Brake Light
First picture is Driver Side Brake Light
Second Pic is Passenger Side Brake Light
Last edited by Zohan; Feb 25, 2013 at 06:59 PM.
Senior Member
Joined: Dec 2001
Posts: 494
Likes: 13
From: Amber waves of grain.
2000 CLK430 Cabriolet
Same thing happens to my old girl. My theory: Seems that the needlessly elaborate design of some of the bulb perches, result in the perches losing their tension, and the bulb momentarily loses contact, and the error code lights up, until the next start up, then the code is gone. Happens to me about 3 or 4 times a year. I think that the next time it throws a code, I'm going to carefully get out of the vehicle and see if I can sneak up on the defective bulb. Likely, I won't be able to, because the loss of contact is only momentary.
I recall that about a thousand years ago when my ride was still under warranty, I took it into the dealer for this same problem, and they quickly replaced the peculiar rear light perch assembly on each side, and new bulbs too. Dealer must have been acting from experience.
There is a lot of needless German re-engineering. Why change from proven and reliable bulb perches to a needless complicated system, especially when the system is so fragile and fickle? That's rhetorical.
On one occasion, lo and behold, I discovered a failed license plate bulb, and changed them both out, but, that's a tale from a bygone era.
I recall that about a thousand years ago when my ride was still under warranty, I took it into the dealer for this same problem, and they quickly replaced the peculiar rear light perch assembly on each side, and new bulbs too. Dealer must have been acting from experience.
There is a lot of needless German re-engineering. Why change from proven and reliable bulb perches to a needless complicated system, especially when the system is so fragile and fickle? That's rhetorical.
On one occasion, lo and behold, I discovered a failed license plate bulb, and changed them both out, but, that's a tale from a bygone era.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,258
Likes: 209
From: Boston North Shore
2001 CLK320 Cabrio
Expect that all your bulbs are OK on full working current, but one of them throws a false failure, when tested by the lower diagnostic sensing current.
This was meant by MB to be a built-in "preventive maintenance" system. When some bulbs are about to fail (e.g. due to socket corrosion, lose/poor connection, out of specification filament resistance etc.), but have not failed yet, at low current the computer will sense the problem and provide a warning. I've read a number of cases, where after the 'lamp failure' triggered with all lamps seeming to be OK, not very long thereafter, a lamp was found to be actually out (e.g. filament burned, lose or dirty connection).
Also check that both of your license plate bulbs are operational. Surprisingly, in 12 years now, I've had no issues with a lamp burning out, except for one of my license plate lamps failing, which triggered the 'lamp out' warning.
This was meant by MB to be a built-in "preventive maintenance" system. When some bulbs are about to fail (e.g. due to socket corrosion, lose/poor connection, out of specification filament resistance etc.), but have not failed yet, at low current the computer will sense the problem and provide a warning. I've read a number of cases, where after the 'lamp failure' triggered with all lamps seeming to be OK, not very long thereafter, a lamp was found to be actually out (e.g. filament burned, lose or dirty connection).
Also check that both of your license plate bulbs are operational. Surprisingly, in 12 years now, I've had no issues with a lamp burning out, except for one of my license plate lamps failing, which triggered the 'lamp out' warning.
