Display Defective, W210, 2002
 

Just got Display Defective (with engine icon) which, per the OM says - "This message is displayed to indicate that the information being relayed by the engine control unit is no longer complete. The coolant temperature guage, tachometer, or the cruise control may have failed."

Everything works on display, and there are zip indications of any failure - i.e. starts, drives, cruise works, tach works, etc. Fluids all OK, including radiator, windshield washer, brake, etc.

There was no additional information via the normal modes on the display - so. tried to reset with the "R" button, but was unable to do so. Tried several restarts and drove it a couple of days - no change, warning still consistently on. No other warnings and nothing ever came up in the "Malfunction" process for reset. Continued to try and reset, but no joy.

Disconnected battery today and left disconnected (both + and -) for about an hour - upon battery reconnect and engine restart, the engine icon went away. However, the two brake related warnings came on ... and, were also unresettable, but DID show up in the malfunction process.

So, I disconnected battery and will leave it disconnected for the remainder of the day.

Have owned car for a couple of years without any issues or warning lights - except for the stupid low quality LCD displays which drop a pixel now and then, but this was happening well before I got it ... other than changing oil and trans fluid and replacing the radio (a year ago) and about 6 months ago cleaning the MAF nothing has been done ... the battery has not even been disconnected (prior to today), no other wiring disturbed, etc.

Other than going to dealer for a scan, what are my options? I would rather put 100 hours into troubleshooting, and buy new tools, than go to the dealer!

Thanks!!

I really need some help!!

Thanks!!

Here's a bump to the top. I'd like to know what this in case it ever happens to my 210.

Thanks!

I just reconnected battery after 12 hours disconnected - no change.

The original warning went out - but, the Brake Assist and ABS warning lights stayed on ... could just be really weird coincidence, but ..... not likely.

I have searched a lot about Brake Assist warning and appears there could be connection to the brake switch (top of the pedal) - but, again, this requires an incredible coincidence.

Maybe related, maybe not.
On my 129, I had a fuse on the OVP blow, causing the brake idiot light and ABS come on.

Come to think of it, I don't even know if a 210 has an OVP.

Might be something to look at.

Don't think my W210 has an OVP - more distributed architecture.

However, my W126 diesel does and I scewed around with it for a year before I final took it apart, cleaned and smoothed the contacts, and resoldered a point or two - then all OK.

Can't help with the display issue; the W210 has a K40 relay that replaced the OVP. Is the first item in the front of the computer box on the right side of the engine compartment. The computer board can develop minute cracks and cause intermittent electrial problems in numerous systems.

Gahhhhhhh ..... this is nuts!

Just restarted it and after having consistently gotten the ABS and BAS warnings for the past 10 restarts, THEY ALL WENT OUT!

Now, clearly, this means they will probably come back since I haven't actually done anything - however, when pulling back into the garage I did use the brakes several times ... maybe this started the brake switch working, again?

Gahhhhh ......!!!!

Here's another possible issue.
I was having various idiot lights turn on occasionally. And at the next start, other lights would.

I bought two new keys. Those problems went away.

But I have no idea if that will fix your issue