Hi Robert,

Since LEDs are diodes, they do not present a plausible resistance to the Lamp Control Module (Bulb Failure Module). You might try testing LED bulbs that are designed to not trigger CAN bus errors - these bulbs have resistors built in to fool computers into thinking standard filament bulbs are connected.

Cheers,

Don

 

Thanks, but that is one very expensive way round the problem - the canbus bulbs (when you can get them) are a lot dearer than the regular LED bulbs and adding resistors to every lighting circuit is just adding a load of 'points of failure' to an already marginal electrical system. I've been down this route before with a Beemer (better electrics as well) and it's a very unsatisfactory/expensive solution. The only area where you have little choice is the indicator/flasher bulbs when you can't upgrade the flasher relay - I've been able to on a MB, I believe you can modify the relay on my Beemer but I understand the flasher is built into one of the ECU's on the X300.
A warning to tell me a bulb isn't working is, for me, unnecessary (I check them regularly) so I would prefer to go to the root of the issue and either disable the check or remove the bulb.

 

Old cars never had the bulb failure feature, so if you are confident that you check all your lights then remove the dash warning bulb.
Fitting CANBUS LED lights would do away with its value anyway because when the LED failed the system would not be able to see it anyway because it would still show the resistance of a working bulb.