My March 2012 reg, 11,000 miles Tit X 'misbehaved' with an erronious warning about a failed headlight bulb on only one occasion since when all has been well. It has to be said that the warning coincided with a (correct) message saying that the tailgate was open and I'm wondering if this has something to do with the peculiarities of the CAN-BUS system.
Whilst reading up on the CREE 5w LED lamps, I found this interesting article which readers might find useful:
"To put this into perspective,what is CAN-BUS? THISexplains it in fancy technical terms.Or in the case of any mark 4 Golf or Bora,it's a digital data network that lets the central locking/electric window module in each door,the CCM (Central Convenience Module),the instrument cluster and on later cars the ECU talk to each other,it's actually kinda like having a small version of the internet in your car.
This is a network that in our case has nothing to do with the car's lighting system,in fact in all cases no light bulbs are directly connected to the CAN and never would be and therefore can't cause errors with it.This is the same as selling household light bulbs and claiming them to be "Internet error free",something which anyone should know can never happen.
This seems to have started with a bad case of Chinese whispers and got a bit lost in the translation from Chinese (they were first made in China).This is significant because some people are starting to blame problems with their cars because they DON'T have CAN-BUS error free bulbs fitted,and think that if they spend money on these little bits of magic,it will cure all their problems
The reason we need the built in resistors in interior light bulbs in our case is because the CCM that controls them needs to see the much lower resistance of a filament light bulb (a couple of Ohms),but doesn't like the almost infinitely high resistance of an LED.This is a problem because the CCM isn't really sure if there's a bulb there or not,so sometimes won't switch it off fully (it will stay dimly lit) and it won't put the +ve supply to it to sleep as it does with the proper bulbs,hence flattening the car battery if left for any length of time.
So yes we do need LED bulbs with the built in resistors for our interior lights to work as they should with the full fade in/fade out action,but this can never have anything to do with our CAN-BUS system and shouldn't be bought as such.The only time I have ever seen car lights cause this sort of error is cheap Chinese HIDs (yes I know!!!!!!).I've also seen them completely kill ALL radio reception in the car,bring up the airbag and ABS warning lights and stop the speedo from working,another reason to throw crap like this in the bin."