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Discussion Starter · #1 ·

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The number plate bulbs are cold monitored by the LKM, you'll get a bulb failure warning light if you use LED's. It's not the low power that will trigger the warning, it's the high resistance when not fully on, you may also find that they are always slightly on.

NavCoder 'may' be able to recode your LKM so you don't get bulb out warnings.

If you want white bulbs then you may be better off with blue tinted filament bulbs.
 

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Stop, stop, STOP!

Why go for cheapo ebay replacement LED bulbs when you can buy genuine BMW LED number plate units?

I've been discussing this on another forum. I've fitted them and built a very cheap, simple circuit to eliminate any error messages.

The LED units and wiring are about £11 per side from the dealership, and the bits for the circuit are a couple of quid each.

If you're interested, I'll post up a circuit diagram and how to.
 

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OK – this is what you need from the dealers:

2x LED Units - 63 26 7 193 293
2x Plug connector - 61 13 6 925 634
4x Bushing Contacts - 61 13 0 005 197

Here’s a pic of one of the LED lamps (ignore the black thing at the end of the wire!):



If you wire up the LED lamps directly in place of the original filament bulbs units, they will light up but you will be faced with two problems:

1) The Check Control will register blown number plate bulbs
2) The LEDs will flash on every 10 seconds or so. This is because the Check Control periodically sends a very weak voltage pulse to the bulbs to check if they’re blown when the vehicle’s ignition is on. The pulse is not enough to light up a filament bulb, so it’s unnoticeable. But it is enough to light up the LED, so you see a flash.

This is why we need to build the following circuit – it supplies the correct resistance to the Check Control, and isolates the LED when the sidelights are switched off. You will need the following components from Maplin:

2x relays - code YX97 - £1.91ea
2x resistors - code H47R - £0.40ea
Some wire



Of course, because we’re dealing with LEDs, polarity has to be observed.

Once the circuit has been built, remove the original bulb housings from the boot lid and unplug them from the vehicle loom. Connect the new circuit to the plugs, connect the LED units and snap them into place in the existing holes. They will be difficult to fit at first because there is a layer of foam which needs to be compressed.

Now, all that’s left to do is wait til it’s dark, stand back, and admire:

 

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Discussion Starter · #8 ·
I sort of get the circuit diagram, this is what im going to do next Monday Im going to order thr parts into my local garage and then install them on Friday. Do i not need any solder tho?
 

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Yes, you'll need to solder the components together. The two black dots with + and - next to them are the terminals of the vehicle loom connector.
 

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Discussion Starter · #11 ·
Arggh thats going to be slightly hard to then, as my dads a builder hes only got the big old gas torch lol, lets me see how much a small soldering kt is but thanks DAN530 i shall be printing this out and doing it in a week :) and to the other guys for their input.

THIS FORUMS GREAT ! :)
 
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