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Mass electrical failures in COMAND 2005 c230 K

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Old Jan 5, 2010 | 05:07 AM
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Mass electrical failures in COMAND 2005 c230 K

hey all. Long time lurker, first time poster. I'm having a multitude of electrical failures on my 2005 c230 kompressor with COMAND console. Here is the list of issues i'm experiencing:

-various light failure messages even though the "failed" lights are actually working
-radio on COMAND only displays "AM 558 or AM 2296" stations. When i attempt to change stations or between am/fm, COMAND stalls, then displays "????"
-cd and dvd drives won't eject. COMAND says there is no disk in CD or DVD drives when those drives are full. Because COMAND doesn't recognize a DVD in the drive, my navigation is useless
-left blinker alternates blinking speeds between extremely fast blinking and normal blinking speeds
-CD changer always skips even on brand new CD's
-sometimes COMAND system won't even turn on
-sometimes (rarely) my key won't turn in my ignition, making me unable to start my car
-my passenger side rear view mirror will tilt downwards when i reverse, but won't return to the original position when i return to drive

It seems like there is a pretty serious electrical issue here. Anyone have any ideas on what the cause might be before i take it to the dealer? Should i take it to the dealer? What might this cost me?

Thanks in advance for all your help.
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Old Jan 5, 2010 | 06:47 AM
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2006 C350 Sport 6MT
I'm gonna go on a hunch here and recommend checking the "Front SAM". All these are controlled by the "Front SAM". Below is the exact procedure the dealer will use to change the "Front SAM". They will use STAR (diagnostics) to determine if SAM is really bad. Try checking for fuses (SAM Fuses), I really hope it's a fuse rather than the FSAM. It can really be from anything. Maybe even COMAND is malfunctioning and causing a problem even with the lights and mirrors.

Good Luck



Last edited by W203E35; Jan 5, 2010 at 06:59 AM.
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Old Jan 5, 2010 | 05:12 PM
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Thanks for your quick and detailed reply...I'll check the fuses but it looks like i'm in for a hefty stealership bill

I can't believe so many systems are failing at the same time...i hope that the problem isn't damaging these components permanently, i'd hate to have to replace my COMAND unit.
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Old Jan 5, 2010 | 06:02 PM
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Something is very strange about the problems you're having. I agree with Karo about the front SAM, but the COMAND unit problems, as far as I know, aren't related. Have you been checking your battery voltage? Maybe it is going. When the battery gets low it can cause issues like this.

The turn signal is meant to work at twice normal speed IF the system thinks one of the signal bulbs are out. You would also be getting a bulb out warning on the display as you mentioned. The lights on the outside of the car should NOT be blinking at double speed, only on the cluster should it do that. If the failure messages are coming from the same few bulbs they could have dirty or corroded contacts. This is a common problem - just clean them with an eraser.

The mirror not returning is also a common problem with the motor tracking.

Did all of these problems start at the same time? Or are they unrelated issues that have cropped up?

On your COMAND unit you can press and hold OK + 7 + MUTE from the aux screen (easiest screen to do it from) to get into the diagnostic menu (it takes a few tries, press and hold them 1 at a time until you are holding all three buttons). Once in that menu you should be able to see if the COMAND unit has any trouble codes stored as well as the voltage and the status of the different CANBUS signals.

It does sound to me like your COMAND unit might be shot. If that is the case you can forget about the dealer. They will want well over $3,000 for it. A new unit can be had on ebay for well under $1000. Hopefully this is the result of only a bad battery or voltage regulator! Please let us know what voltage you are getting with the car off and with the car running at idle as well as when you increase RPMs.

CD changer skipping is probably unrelated. Try a cleaning CD. Otherwise it may be misaligned and also shot.

Key not turning could be part of the SAM issue or it could be a bad EIS module. These are all potentially very costly problems.

Last edited by acr2001; Jan 5, 2010 at 06:11 PM.
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Old Jan 5, 2010 | 06:43 PM
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thanks again acr2001 and karo. I'll definitely check the COMAND unit diagnostic codes and post them here when i get them.

As far as the battery goes, my battery did go out recently, but i took it to a sears auto center and they checked the battery and battery diagnostic said "BATTERY OK VOLTAGE OK, LOW CHARGE" and i had it charged, so i don't think the battery is at issue here, unless i'm wrong.

There is another issue that i neglected to mention. There seems to be a parasitic power draw in my ignition. My batteries in my key remote last 2-3 days tops before they die...don't know if this helps at all.

Thanks again for your help.
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Old Jan 5, 2010 | 07:08 PM
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dam man what did you do to your car. I wish i could help but i have no clue though. did the problems come right after sears or a while later. as for the key that is strange becase all the batterys do is do the unlock and lock part of the key. nothing to do with the starting part. the eis actually powers the key for the starting part. how long have you had this car?
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Old Jan 5, 2010 | 09:08 PM
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Originally Posted by PATSCRU
thanks again acr2001 and karo. I'll definitely check the COMAND unit diagnostic codes and post them here when i get them.

As far as the battery goes, my battery did go out recently, but i took it to a sears auto center and they checked the battery and battery diagnostic said "BATTERY OK VOLTAGE OK, LOW CHARGE" and i had it charged, so i don't think the battery is at issue here, unless i'm wrong.

There is another issue that i neglected to mention. There seems to be a parasitic power draw in my ignition. My batteries in my key remote last 2-3 days tops before they die...don't know if this helps at all.

Thanks again for your help.
You may very well have a bad battery. I've gone through this same issue with a previous car where I had it load tested and they told me it was fine. Got stranded 3 days later because the battery was SHOT. How old is your battery?

The fact that your keys are losing a charge every few days tells me that your EIS is not powering them properly. The EIS has an induction coil in it that should power the key while it is inserted, as samaritrey said. I believe your EIS is not powering the key when it's in the ignition, so this is draining the batteries. Your car really seems to be a huge mess! You need to start by monitoring your battery voltage. It's probably part of the problem.

Can you give us more details? Did all of these problems start at the exact same time? If so, when?

I'm going to go out on a limb here.... but it sounds like your battery may have been connected backwards (reversed polarity) since so many systems are showing signs of electrical damage.

Last edited by acr2001; Jan 5, 2010 at 09:11 PM.
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Old Jan 5, 2010 | 09:47 PM
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Originally Posted by acr2001
On your COMAND unit you can press and hold OK + 7 + MUTE from the aux screen (easiest screen to do it from) to get into the diagnostic menu (it takes a few tries, press and hold them 1 at a time until you are holding all three buttons). Once in that menu you should be able to see if the COMAND unit has any trouble codes stored as well as the voltage and the status of the different CANBUS signals.
How do you get it out of this menu mode ACR2001? I use a Coleman plug in volt gauge every so often in the 12 volt outlet under the HVAC...This way through COMAND maybe even better than when I monitor the electrical at the battery terminals...

- IF the battery needs to be replaced, I have read that the REAR SAM can be damaged with improper process and load retention...

Good luck OP - Let us know what you learn!
Jake
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Old Jan 6, 2010 | 10:39 PM
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Originally Posted by BF_JC230
How do you get it out of this menu mode ACR2001? I use a Coleman plug in volt gauge every so often in the 12 volt outlet under the HVAC...This way through COMAND maybe even better than when I monitor the electrical at the battery terminals...

- IF the battery needs to be replaced, I have read that the REAR SAM can be damaged with improper process and load retention...

Good luck OP - Let us know what you learn!
Jake
If you do as I said above ... when you find yourself on the home screen of the menu (it will say Alpine test menu on the bottom if i remember correctly) one of the soft buttons on the lower right says something like "status" or "signals" ... when you press that you will get info about the canbus status, the temperature of the comand screen, voltage, etc.

Feel free to mess around in any of these menus as you really can't do any damage to anything. The worst thing you could possibly do is get into the test menu for the buttons. From there none of the buttons on the comand unit will work (including the on / off button) but simply pulling the key out will reset this with no problem. You can cycle the key on and off at any time to get out of any of the hidden comand menus should you somehow get stuck. You can also reboot the comand unit and the seperate (but built in) navi unit from these menus.

You know you can also get the voltage from the gauge cluster, right? With the key in position 2 and the engine off, go to the screen that shows your mileage, and press the reset button three times very fast. The display will beep and take you into the menus that show your oil level, voltage, vin number, software versions, etc. On my car though, the voltage shown in the gauge cluster is not the accurate battery voltage. It's ~1 volt too low. Not sure why this is. My comand unit does show the proper voltage compared to my voltmeter.

Last edited by acr2001; Jan 6, 2010 at 10:42 PM.
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Old Jan 7, 2010 | 01:39 PM
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w203
Hey all,

I was able to get into the diagnostic mode and write down all the voltages and error codes (they're in my car but i'll post them soon). However, when i started my car again. My COMAND unit completely stopped working. The screen went off and would not turn on. All the buttons weren't lit up except for the EJECT button. When i pressed the eject button, the faceplate opened and but i wasn't able to eject the cd and dvd.

Looks like my comand unit is going kaput.....
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Old Jan 7, 2010 | 10:09 PM
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Originally Posted by PATSCRU
Hey all,

I was able to get into the diagnostic mode and write down all the voltages and error codes (they're in my car but i'll post them soon). However, when i started my car again. My COMAND unit completely stopped working. The screen went off and would not turn on. All the buttons weren't lit up except for the EJECT button. When i pressed the eject button, the faceplate opened and but i wasn't able to eject the cd and dvd.

Looks like my comand unit is going kaput.....
I don't have enough info to say this for sure, but my best "stab in the dark" at a guess right now would be that your voltage regulator is shot and all of the electrical components in your car are seeing a power surge when the alternator gets to higher RPMs.

If this is the case, you are causing further damage every time you start your engine. Please post the voltages you got with the engine on and off. Also, remember that the error codes stored on your comand unit are comand unit specific errors, not the same as the errors stored in the main ECU.
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