The speedo - dashboard display

Note: Follow these instructions to remove the Citroen C3 speedo display to get to the point shown below.




The Citroen C3 speedo and dashboard display has a tachometer (rev-counter), speedometer, odometer, trip meter, temperature gauge, fuel gauge, indicator repeaters, two switch inputs and various warning lights. There are several different versions of dash display fitted to cars of different years. This is an early version of speedometer dashboard display.
There is a single, multi way connector on the rear that carries the can/van bus signals to the electronics inside. This is a sagem unit part number P9650735480


The circuit board is held in place by several small torx screws and contains the moving coil meter for the tachometer - rev-counter, the logic chips and all the LED lighting elements for the display. There are no lamps or light bulbs in the speedo display, the back lighting and information/warning displays are illuminated by SMD LEDs. The greatest advantage of the SMD LEDs are they have a very long life, longer than the life of the car, they have a low manufacturing cost, low power consumption and integrate well with automated production systems.


This shows the arm that is part of the rev-counter
and this is the opposite side of the board showing the SMD LEDs and the large white unit that drives the rev-counter arm.

Hi,

Do you know the size of the small torx screws to remove the circuit board?

Thanks!

JC3

Do you know the size of the small torx screws to remove the circuit board?

T8 is a bit small, but T10 is a bit big, so I would say its a T9 Torx, but I didn't have a T9, so I used a small flat bladed screwdriver to remove them as they are not very tight.

Hi,

followed you guide in looking at the dashboard as i have a problem with the AIRBAG warning light not lighting up when key is turned, bought the
car second hand so was advised it could possibly be that someone has stuck tape over light but checked and thats not the case, now iv put it all back together and the lcd does not show anything, I'm thinking i have put it back in wrong way or the little board that is behind the lcd has been put back in wrong, do you have a picture of the lcd part of the dash board from the inside?

thanks James

00James00 wrote:Hi,

followed you guide in looking at the dashboard as i have a problem with the AIRBAG warning light not lighting up when key is turned, bought the
car second hand so was advised it could possibly be that someone has stuck tape over light but checked and thats not the case, now iv put it all back together and the lcd does not show anything, I'm thinking i have put it back in wrong way or the little board that is behind the lcd has been put back in wrong, do you have a picture of the lcd part of the dash board from the inside?

thanks James

Its is a good idea to take photos along the way if you are doing a job for the first time so you can refer back to them.

These are the pictures of the LCD in the display and the board that it attaches to.

LCD fitted to board LCD Removed and showing the board connection LCD in its holder And this one is checking the symbols are not obscured.
These ones look fine. The colour is generated by the light, rather than by a filter.
And this one tries to show the circuit board, the glass LCD panel and the conductive rubber strip (zebra) and how they interact. Ignore the letters, this is not the LCD from a C3, but its a good description of LCD connections in general.

Hi

Thanks for the reply i think i may have put the white conductive rubber strip in the wrong way, causing it not to work as the vertical black strip on the rubber was at the bottom facing the lcd or maybe i have put the lcd in the wrong way,, ill take another look tomorrow.

the plan was to take photos but due to finishing work late i had a bit of a rush but from now on ill do the step by step photo as i am literally new to this.
Again I'm a complete newbie to motoring in general but am very grateful for all the info that everyone has gave

To be honest looking at the Lcd in its holder I put it back I the correct way? Would you firstly put the lCD in then the rubber strip then the circuit board on top

00James00 wrote:To be honest looking at the Lcd in its holder I put it back I the correct way? Would you firstly put the lCD in then the rubber strip then the circuit board on top

Yes.

This is the problem I'm having, which way to the white board with black strip fit onto the back of the LCD,

Please ignore last post I didn't realise exactly where the board went but figured it out lol