450 Installing Interior LEDs And Bulbs

Most of the lights in the smart car dash are 509T twist fit bulbs, these range in wattage from 1.1 watt to about 1.5 watt. Replacement 509T twist fit LEDs can be fitted in place.

Where Can I Get 509T LEDs?

Unfortunately, EvilLED as a company never really stuck around for long. Their LEDs were excellent but they were nigh on impossible to get hold of so now it’s time for a new supplier.

Forget UltraLEDs, Forget M-99. I have used both and wasn’t impressed by the quality. I haven’t tried this company personally but have read good things about them. If you use them, let me know what you think about the company and the product quality.

Centre Console Courtesy Light

To remove the light put a knife under each side of the lip and lever forwards.

Once out the bulb can easily be seen (circled in red), replace with any colour LED in a standard 509T twist fit housing.

Make sure the LED works, if not, remove and turn 180 degrees before refitting. When it’s all working simply clip back into the console.

It is worth noting that there is a residual voltage running through the lower courtesy light at all times, a normal bulb is way too inefficient to glow at these low levels but an LED can. You will notice a glow even when it should be off, don’t worry, it won’t kill the battery.

Speedo LEDs

Firstly you need to equip yourself with the correct tool. You will either need a T10 torx bit or a 1.5mm allen key, they have to be quite long.

You will also need the twist fit socket (found on the rear of the speedo), 11/32 socket or a set of long nose pliers and some LED 509T twist fit replacements in whatever colour you like.

Use either your T10 bit (T10 screwdriver) or 2mm allen key in these holes (circled) and on the same 2 on the other side. The screws are quite far in.

Put your fingers right on the edge as pictured and pull slightly towards you to free the housing, do this the other side too. The whole housing containing the speedo will now be loose, lift it and turn it clockwise and rest it on the dash.

It is not recommended that you disconnect any wires to aid fitment unless you have to. The reason for this is that some speedos can revert back to showing kilometres.

Disconnecting the RPM gauge (circled red) can sometimes cause it to be inaccurate but it can be fixed by looking. Disconnecting the other cable (circled green) can sometimes cause the odometer to revert to kilometres, smart can fix this.

Bulb Number	Main Light Function	Alternative Light Function	Bulb
1	Engine Check	Service	12V 1.1W BX8.4D
2	Oil Warning	Mains Charging	12V 1.1W BX8.4D
3	Glow Plug	Seat Belt, Exhaust Temp, Stop	12V 1.1W BX8.4D
4	Battery		12V 1.1W BX8.4D
5	Rear Screen Heater		12V 1.1W BX8.4D
6	Indicator		12V 1.1W BX8.4D
7	Airbag		12V 1.1W BX8.4D
8	ABS		12V 1.1W BX8.4D
9	ESP	Trust, Trust+	12V 1.1W BX8.4D
10	Brake		12V 1.1W BX8.4D
11	Rear Fog		12V 1.1W BX8.4D
12	Full Beam		12V 1.1W BX8.4D
13	Speedo Backlight		12V 1.1W BX8.4D
14	Speedo Backlight		12V 1.1W BX8.4D
15	LCD Backlight		12V 1.1W BX8.4D
16	LCD Backlight		12V 1.1W BX8.4D

These are best removed with the supplied remover.

Look to the right of bulb 13 and you will find a plastic tool attached to the back of the speedo, twist it off. This fits the 509T bulbs perfectly.

Twist them a quarter of a turn anticlockwise and pull the bulb out.

Using the 11/32 socket (which holds many new LED holders nicely) or the long nose pliers, insert and twist a quarter turn clockwise. Once they are all fitted check the lights, any that don’t light will need removing and rotating 180 degrees before refitting. When all the
lights work (you may need to fiddle with them a bit) reassemble the speedo pod.

The LCD shows up really well but the speedo can be very patchy using LEDs, this is because the LEDs fire forwards in a narrow beam. This causes bright spots in places.

LCD Phasing Effect

You may notice a slight phasing from the LCD but it is slight, John in Lincs was good enough to email me and offer an explanation for the flickering effect.

‘The LED dimming method used on the Smart is PWM (Pulse Width Modulation) what happens is that the instrument lighting is switched on and off at high frequency for example 1KHz, 1000 times per second. The length of the ON time is adjusted by the circuit from 1MSec downwards, 1MSec=fully on, 0.5MSec = half brightness etc. The LCD in the display is also modulated i.e. digits are switching on and off at high frequency, if the two frequencies are nearly the same you get a strobing effect’.

Dash Pods

Firstly remove the coloured outer ring, they clip straight on and come off easily.

Place a thin headed screwdriver next to 1 and 6 on the tacho (3 and 9 on the clock) and lever to unclip the 2 clips (circled in red).

Lever the hands off with a strong fork

Place the knife down the side of the dial and slowly lever both sides.

Going from side to side the dial and backing will slowly come up and come out. If you have aftermarket dial faces they can be fitted now, to fit the speedo dial, look

.

With the dial out of the way, carefully unclip the ribbon connector from the circuit board. Using your thumb, bend back 1 clip at a time (circled in red) and pull the PCB forwards.

Circled in red is the 509T twist fit bulb that you can change, these also take the standard twist fit bulbs used in the speedo console.

Problems and Ideas

The main problem with using LEDs in these pods is the angle of diffusion.

The standard bulb shines light around 280 degrees whereas the LEDs lend to go from about 70 all the way to 5 degrees for the high brightness.

In this case the dial is lit by the plastic which acts as a light tube, unfortunately the light tube is lit from the sides so the LED won’t light it properly. This is the cause of the dim dials that have been reported by many people attempting an LED swap.

Thanks to Joao Paulo for the following info:
On the 2nd generation smarts the pods have a yellow/orange filter in them, this means that if you try to use blue LEDs not much comes out. The same applies to white LEDs, they only a create a very dim yellow/orange tint light’.

At the time of updating this page there is a new LED design on the market called the Inverted Cone, this outputs a lot more light from the side but isn’t available in a 509T.

It seems the best way to go is custom home made lighting, due to the space in the dial it looks like SMD or 3mm LEDs will probably yield the best results.

Ideally you should fit some Metal Monkey dials instead and the LEDs work really well.

Rear Courtesy Light

The rear courtesy light is by far the easiest to change. Insert a flat screwdriver into the front edge and lever open, the whole lens will fall away.

Lever the 2 white clips (circled) inwards, this will come away to reveal the connection.

The holder accepts 36mm to 39mm festoon style lamps and LEDs.

Because of the direct nature of the light, the replacements are very bright. It is worth noting that some colours make reading maps etc very hard.

The new 36mm to 39mm festoon style LED bulb (shown above) can simply be pushed into place. Again, if it doesn’t work turn the whole unit 180 degrees and refit. Painting the original bulb with blue glass paint gives a very good white light compared to the standard bulb output.