C250: Lot's inoperative, fan noise and can't change out of park

[tommy060289]

Hi everyone,

I got in my car (W204 C-Class C250 2012 150,000 miles) this morning to go to work and have received quite a severe fault out of nowhere.

The car made a beep noise and gave me a long list of inoperative systems which are:

- Cruise control and SPEEDTRONIC inoperative
- Parking Guidance inoperative
- Restraint sys. malfunction Consult workshop
- ABS and Traction Control (Symbols) inoperative See Owner's Manual
- PRE-SAFE Inoperative See Owner's Manual
- Run Flat Indicator Inoperative

Also the stereo system does not come on and the car can not be shifted out of 'Park' so is obviously undriveable. After about 30 seconds I can hear a fan kick in and that is quite loud.

Im guessing by the sudden and random nature of this that it is likely some sort of electrical fault but does anyone have any idea what is the likely culprit. I had a quick google around and one suggestion was as simple as the battery but guessing could be one of many things so if anyone can give me any guidance before I end up shelling out a fortune to a Mercedes repair place it would be much appreciated!

Cheers,

Tom

 

[oldguy57]

First thing I would do would be to check the voltage of the battery before and after starting, should be in the order of 12.5 and then 14.5.

 

[markjay]

As above. Possible battery or alternator failure.

 

[CowleyStJames]

Gotta agree with old guy. Battery faults on these cause all sorts of random issues.
Charge battery and see how it goes.
Colder mornings now put a marginal battery in its grave.
Even if it all works after charge, replace. It's near its end of life

 

[tombell]

I had something similar and was emailed by the club a couple of months or so ago as one of the members had same sort of trouble as I had a couple of years ago. when I turned on the engine the fan roared flat out and I cdnt get into gear and the dash was full of error messages. I have an E220 C207 Coupe 2012. I had to lift up the leather at the rear of the auto gear stick and press down on the yellow button underneath to get it into gear. It turned out to be a RELAY which is housed under the main battery under the bonnet. You can't just buy the relay you need to pay £200 for a unit which contains it then find someone to fit it for you and all will be well... my car is still running fine.
Before I bought the RELAY, just to keep the cat going, i had to fit an in-line switch to the EARTH for the small battery under the boot floor. Every time I had the problem I just switched it off , counted to ten and turned it back on again and it worked fine.
Also, before I bought the relay I wasted £240 on a new battery but that didn't solve the problem.

 

[BenEC]

Just came here to add to this. Had the same issue with my 2012 C250 Coupe last week: Multiple errors on the dash:
- Restraint sys. malfunction consult workshop
- Active bonnet malfunction see owner's manual
- PRE-SAFE inoperative see owner's manual
- Run Flat indicator inoperative
- PRE-SAFE functions limited see owners manual
- cruise control and SPPEDTRONIC inoperative
The engine would start but the central display would also not power on, the fans on the engine were at full speed at I could not move the gear lever out of park. It had been driving completely normally that same morning.
I was stuck at the shop so I had to pull off the leather cover around the gear level and use the little yellow button to get it into drive
drove it the short distance home with no power steering and no indicators and the fans going crazy
Got it into my local independent Mercedes garage (East Bristol) who I use regularly and who fixed it free of charge. They told me it was a dodgy cable connection but didn't specify exactly which one. Must have been either shorting across pins, to chassis or simply going open circuit and flagging comms errors in one of the engine modules, causing the vehicle to go into some kind of safe mode.

Hope this helps anyone who gets this problem.

 

[optimusprime]

If this is anything to go off --it surprised me at the time .