I'm a new member to this forum and I would like to thank its members for valuable information. My '98 E320 was giving me a Lamp Defective warning message, although all the bulbs were lit. I first checked a number of threads on this topic and learned that even though a bulb may light, it still may cause the warning message indicator. The message said to look for a darkened bulb, even though the filament may be good. That was exactly my situation. I replaced the bulb and problem resolved. Thanks again!

__________________
Dave

1998 E320
2001 SLK320
2000 Lexus RX300