Just started yesterday. Radio works, the COMAND display buttons work, but the screen is blank. No backup camera display. Tried the COMAND reset by holding down the On button. Checked fuses 11 and 24. Ran my iCarsoft scanner and it came back with 3 faults -

D185 Communication with the Audio/COMAND Operating Unit has a Malfunction.
C264 Communication with the Backup Camera has a Malfunction.
C255 Communication with the Audio/COMAND display has a Malfunction.

I read online that a low voltage situation will cause problems with COMAND. The battery voltage was reading 12.1v and the battery looked pretty old, so I got a new Duralast batter and put that in. Crossed my fingers that would fix the problem, but no dice. Any other ideas, or am I looking at trying to get another Comand unit? I'd think if it was bad I wouldn't have any functionality.

 

Maybe Auxiliary battery? @CaliBenzDriver I need your help!! 😄

 

You're doing very well in your "process of elimination"... not your first picnic!

-- What is the module that calls the 3 fault codes you've found ?

-- In what fault status : ACTIVE or STORED ?

-- Any other seemingly unrelated faults that can seriously messup CAN-B ??

>> we are inching our towards CMD or display...

​​​​​​-- Go ahead and read data from these modules with your interactive scanner?

-- how does that go.... ?

Lets review all this.

 

After clearing the faults and rerunning the scan, I have two current faults (D185 and C255 from above). They show as active and historic.

The backup camera fault went away, though I still don’t have an image on the COMAND display when engaging reverse.

No other faults were found.

The attached images list the information for the module.

 

It looks like that module number is for the COMAND head unit itself. If it's getting voltage to the unit, I'm really afraid I'll have to replace the head unit. You can find used ones off eBay for $350 or so, but I think you need to ensure you get a PIN from the donor car or it won't work.

 

I was asking what module is calling these two faults... i don't think COMAND is calling fault about not accessing itself.

It seems you do have normal access to unit over CAN-B.

We know these Mitsubishi unit fail like clockwork for unknown reasons (caps, heat, solder, boot)

I addition display unit is a super hot module cooled by a small fan.

I am NOT comfortable recommending either module without hard evidence ... personally I would rather get my unit recertified instead of getting an old one ready for same game

 

Maybe it's a limitation of my scanner, or my ignorance of the complex MB electronics, but it did not say which module called for those faults. There is an option for an actuation test of the unit but it ironically called for providing inputs via COMAND, which is kind of hard to do when you can't see anything on the screen!

I'll look into finding a shop that can diagnose and repair these units. Definitely not going to the dealership and paying $5k for a new one.

 

The only place that can provide that service besides an independent MB dealer will be an independant MB specialist.... not a general car stereo shop.

I don't know your iCarsoft scanner, perhaps @JettaRed has time to help you extract more information. He's very familiar with it.

 

Welp, started the car this morning and, lo and behold, the screen was working! Not sure what happened, but I’ll take the win (fingers crossed it doesn’t pop up again).

 

can we say this is not a hard failure
then is more like a soft-crash
the type that's caused by CAN-B traffic jams