Instrument cluster lights up but none of the gauges move

Chaud

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#1
Make
Mercedes
Model
C230 4 door sedan
Year
1997
Miles
152K
Engine
4 cylinder
All the dashboard analog gauges not working even though it lights up when key turned to one or two position . I noticed digital odometer works. Checked all the fuses in the box in engine bay by driver side and they all are good. Battery is fully charged. I don't know where to look next. I will appreciate your help to fix this problem. Thanks
 

nickb2

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#2
All the dashboard analog gauges not working even though it lights up when key turned to one or two position . I noticed digital odometer works. Checked all the fuses in the box in engine bay by driver side and they all are good. Battery is fully charged. I don't know where to look next. I will appreciate your help to fix this problem. Thanks
 

nickb2

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#3
All the dashboard analog gauges not working even though it lights up when key turned to one or two position . I noticed digital odometer works. Checked all the fuses in the box in engine bay by driver side and they all are good. Battery is fully charged. I don't know where to look next. I will appreciate your help to fix this problem. Thanks
 

nickb2

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#4
Ok, thats much better. Hows things Chaud?

Lets start by attacking the obvious. Analogs not working, but lighting and digital does.

Lets start with the wiring. Here it is in PDF.
 

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nickb2

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#6
To fix this issue, you will need alot of patience if you don't have a capable scanner.

This is probably a can line problem, even a eeprom problem within the dash. But to confirm that, we would like to get the ability to communicate with a bi directional scanner to see if we can actually ask the microprocessor involved to move said analogs that are not working. Most likely, some form of communication error will have been registered.

This snapshot is unique to german pointing instruments, which means in laymans terms, analog. Screenshot (286).png
 

grcauto

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#8
How about telling us which gauges are not working and we can take it from there. Depending some may be digital/analog depending on the build date so it would be best for you to identify which are analog. I have this vehicle in my Mitchell and I'm very adept at using their wiring diagrams.....Alldata leaves a bit to be desired so I don't have them and the one Nick provided is in sections that will drive me to drinking to try and follow them. I appreciate his willingness to share. Now that I think about it you could try printing them and piecing them together if you can build it and know how to read it that would work. If not, tell me what gauges and I can show the circuit flow and post it back to you.
 
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grcauto

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#9
BTW Did these fail at the same time? The analog gauges probably share a common ground in the cluster. I remember taking BMW and VW clusters out and soldering all the grounds and any cold solder joints to resolve some of these problems. You may want to try this first. It's easy enough and doesn't require any special tools other than a soldering iron/pencil.
 

Chaud

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#10
So, As you see, you will need to be very patient, as I do not think any single fuse is responsible for you problem.
Nick, thank you so much for helping me with this excellent information. I am doing well just getting old.
I agree with you it is a communication problem between the cluster and ECU. Somehow the data in eeprom got corrupted and comm. link broken. So how to reprogram this eeprom. I was thinking just like we reboot our computer or cell phone and sometimes have to take out the battery so that internal nodes inside the circuit could be discharged. So I am thinking let's take the pos. terminal of battery off and ground it for 30 seconds and then reconnect to the battery again. With no power all the data in eeprom will be lost and internal software will kick in to reprogram it to factory condition when power restored hence establishing the link with ECU. I am not sure it will work but worth the try. What do you think?
I understood the diagnostic section how to perform the test but checking all the function from the circuit diagram without good scanner will be very hard. You are right it is job with lot of patience. Thanks again.
 

Chaud

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BTW Did these fail at the same time? The analog gauges probably share a common ground in the cluster. I remember taking BMW and VW clusters out and soldering all the grounds and any cold solder joints to resolve some of these problems. You may want to try this first. It's easy enough and doesn't require any special tools other than a soldering iron/pencil.
 

nickb2

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#12
I am doing well just getting old.
Aren't we all?

Yeah you could try that, if it works, great. But since grcauto asked, did they all quit at same time? You wrote ALL analog not working. If they all quit at same time, highly unlikely all those stepper motors quit at same time. So probably an internal cluster problem as lights and digital work, right? They all share common W1 ground, some other stuff use other grounds like W16 in trunk etc, but you probably want to focus on cluster itself.

Many, many benz owners shell out $$ for this same problem. They all seem to fail after a few decades.

If resetting the eeprom with a quick reset procedure work, right on, but you may need to remove it and do some pin testing. I just bought a power probe 4, sweet thing, also bought the 5v adapter for very much problems like this. You could try giving it some juice to the PCB board at the back with something similar to a powerprobe that you can make at home to excite the stepper motors, see how they react. If they react, then you probably have a faulty PCB board or corrupted eeprom and can't communicate via CAN line, thus losing whole cluster for analog.
 

nickb2

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#13
I like to fix pcb's in my spare time for tv's and such, but I have yet to find a proper source of info for anything vehicle related in this dept. Car manufacturers seem to keep these under a tight lid.

I had a funai tv that gave out a few months ago, took me two minutes on google and I had all the PCB schematics printed out. Good luck trying to find one for a benz of your era, any era for that matter.

I know I sound defeatist, but it is just a simple known fact in the automotive world. Most of this stuff is trial and error, and usually end up with a new/used one, or sending it out overseas or something to get them refurbished. I know of no one who does that near me, or even in montreal, one of our biggest cities in quebec.
 

nickb2

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#14
But asking for codes would be a grat help, you may have a u code in there that is denying acces to certain things. These german cars a finicky that way. Just clear everything in all modules. I like your train of thought, half the time, it works, but some other odd gimmick will code a U code and something else gives out like your windows not working in the down position cuz a said door module glitched.

Gotta love german. They love + - bus/can line to work across every module. One gives out, every other module seems to develope a problem. You should see the new stuff. Ouch.