Between 2007 and 2008, smart changed the design of the LCD display in the Instrument Cluster quite significantly. More information can be found here but perhaps the biggest frustration amongst smart owners was the omission of the water temperature gauge. This omission can prove fatal for MHD engines which can suffer from alternator belt failure. Without the gauge, the first indication of rising temperature is when the warning light comes on. If you don't stop immediately, you can incur all sorts of engine problems including a warped cylinder head. An expensive fix.
In this guide, we are replacing an LCD display on a 2009 MHD Passion with that of a 2007 Turbo Passion. We would like to thank Shawn (2minits) who kindly provided the display and inspiration behind this guide.
Although it is possible to fit the LCD to a CDI (diesel) the bad news is that the temperature gauge will not work. This is because the CDI was never intended to have this particular LCD and therefore the input to the instrument cluster from the EDG (the diesel's ECU) has been removed. We would like to thank Jean for bringing this to our attention. :)
Firstly, check the readout values on your current LCD display by pressing the left button on the Instrument Cluster and note these down. You will see that they remain the same at the end of the guide.
1. Total Mileage & Trip Mileage:
2. Outside Temperature:
3. Service Interval (double press the button):
Fortunately, smart didn't change any of the mounts between the LCDs so it really is a simple swap.
More information on how to disassble the instrument cluster can be found here. Stop once you have removed the LCD. Compare the two LCDs. They look pretty much identical.
If you hold them up to the light, you will see the warning icons in the same place on the right hand side.
On the left hand side, we noticed that the 2009 display had an additional icon for fuel cap removal. This wasn't an enabled function on the 2009 fortwo so we didn't mind that the 2007 display didn't have it.
Fit your new (older!) LCD display. The ribbon cable will fit into the connector. Push down the black connector surround to lock the cable into place.
Reassemble the instrument cluster and fit it back to the car. As you connect the wiring harness, you will hear a buzz of the speedo needle resetting itself.
Switch on the ignition and test!
You will see that after a short drive, the water temperature gauge will start to climb correctly. Under normal driving, 3 or 4 bars will be illuminated.
Scroll through the display functions using the left button on the front of the instrument cluster and compare these with those you noted down earlier. With the exception of temperature (which may have gone up or down a degree or two) the values will be exactly the same.
1. Total Mileage and Trip Mileage:
2. Outside Temperature:
3. Time:
4. Next Service (double press the button):
This is an effective guide but does rely on obtaining an LCD display from a 2007 model car. These are not sold seperately from the instrument cluster so they are hard to find. Your best bet is to get a cluster from a breakers or from someone who has fitted an aftermarket LCD display.
