shan

Hi, mine is a 2007 facelift C180. Lately I had the a/c evaporator coil behind the dash changed. Now the Multifunction display freezes and becomes distorted as soon as I insert the key. This is not the old amber display that fades away. Could it be as simple as the a/c guys not having fit the wire sockets tightly or something major? It only happened about a month after the a/c job.Any help is appreciated.

rnd_ash

Being someone who plays with the MFD for hacking purposes, I'd say if it's doing that it's broken.

The MFD only accepts certain input data from various modules round the car, and it validates the data before displaying it first.

As your screen looks corrupt, it's safe to say that it is the problem, however the Instrument cluster itself could also be to blame (it holds the computer used to drive that display)

Regards.

slammer111

Check the ribbon cable for the display inside the cluster. If there are no issues there, unfortunately the entire cluster (or the circuit board at least) probably needs to be replaced as the circuitry has been damaged.

Are you saying the problem suddenly appeared one day, about a month after the evaporator core job?

shan

Yes, it just happened all of a sudden. When I leave the car locked and returned sometime later, the display is normal a while showing all current readings, the clock and the trip meter. Once I insert the key, things start getting murky/distorted and I cannot scroll the screen. And today the display has gone dead completely.

shan

I have now removed the instrument cluster. How do I remove the lcd display to inspect or replace it? Do I have to remove the needles in the meters and take the whole circuit board out?
Thank you in advance.

shan

I have found a used instrument cluster of the same PN as mine, MB A 203 540 87 47 xxxxxx. But when I fit that to the car, the odometer reading goes -----------. I was told that I must go to the dealer to reprogram the cluster.
Can I, if I could, just take out the display unit from this cluster and fix it to my original cluster without the need for reprogramming? Looks like I have to remove the needles from all the 4 meters to get access to the display and its ribbon connector. Any thoughts please.

Rudeney

As an anti-tamper measure, the odometer values is stored redundantly in the ISM (cluster) and EIS (ignition switch). If they ever disagree, you get dashes on the ICM. So, your donor ICM's odometer does not match your IES and this is what you have. The dealer cannot fix this. SDS (Star Diagnosis) will not allow the odometer value int he ICM or EIS to be changed once it reaches a certain value (something small, like 11 miles, or maybe it's 60?). There are two ways to use a donor ICM. One is to transfer the EEPOM chips(s) from your original ICM to the new one. This required removing the circuit board and doing some very detailed "micro-soldering" on very tiny, delicate electronics. The other method is to electronically zero out the odometer value in the ICM's EEPROM. There are special (and expensive) tools that can do this. There are several companies int he USA that will do this if you send them the cluster. They generally charge around $200. Once the ICM's odometer is zeroes, then SDS can be used to "marry" the cluster to the car which will copy the odometer reading from the EIS.

shan

Thanks , Rodney. I will try to get the LCD only from the wrecker's cluster and fix it onto mine.
Hopefully I can do it without damaging the meters and hopefully it will work without having to be reprogrammed.

C230 Sport Coup

There are others who can reprogram these, such as Palo Alto Speedometers in
you guessed it, Palo Alto CA.
They will transfer data from old to new.
I went there once...my panel seemed dead.
Amazingly it came back to life after they put it on their test rig.
Go figure.

KevinH2000

You may be able to transfer the code from the EPROM in your car to the one in your donor cluster. I was able to do that with my Boxster when I upgraded from the 3-gauge Boxster cluster to the 5-gauge cluster from a 911. You can read about it here: http://986forum.com/forums/boxster-g...auge-swap.html

The Porsche clusters are made by VDO. If Mercedes used VDO to supply the W203 clusters the design is likely to have similarities and you may be able to use similar processes to swap the code between clusters. Swapping the code may be less prone to error than removing and transferring the chip.

shan

Good news guys and thanks again to Rodney. I swapped the lcd display unit from the wreckers cluster to mine. Thank God, it works beautifully, including the original odometer reading.

But there is a problem. I don't seem to be able to set the needles at zero. Every time I take out the cluster to set the readings at zero, they go back to below zero when the cable is connected.

Is there anything I am missing out?

Thanks.

Rudeney

Set them with power applied.

shan

Thanks, Rodney.

shan

Thanks again, Rodney. All systems go. The zero readings are a teeny weeny bit off. I suppose at my age my hands are not that steady. I don't want to redo the whole thing again, worried may cause some irrepairable damage. I can live with that tiny off readings.

Big thanks to everybody in the forum who chipped in.

C230 Sport Coup

All's well that end well. Happy Holidays!!