Range of electrical faults - no codes! any advice?! 2010 E250

[HairyBreeks]

Hi All,

I have a range of odd electrical issues on my 2010 e250 cgi and hoping someone with electrical knowledge can give me a few pointers..

The issues are all intermittent and never show any messages on the dash - things like;

• Windows stuttering or stopping (when holding button constantly a single direction)
• All speakers cutting out completely. Turning stereo off and on makes them work again
• FM radio signals all disappearing - then reappearing (FM amplifier cutting in an out basically)
• Key sometimes has no effect (car wont crank) - then starts working again.

My car does not have an AUX battery, and the main battery has been replaced, and I've checked there is good charge from the alternator.

My question is - Is there a way to track this sort of thing? An MB indy reported no fault codes showing up so that seems a dead end.

Would intermittent things like this usually give a code, and if not where does one start in trying to track the source of the issue down? SAMS unit replacement?

The earthing points I can find look ok and I cant see any damage / corrosion to visible wiring.

The alternator has had a oil leak into it in the past, however is charging the battery fine. (steady 14.4v when engine running - occasionally spikes up to 14.9v which I've read is normal).

Or is it a case of auction the car, accept the loss and move on!

Many thanks in advance

 

[geoffus]

Did your problems start after your battery was replaced, or were they already there ?

 

[HairyBreeks]

Did your problems start after your battery was replaced, or were they already there ?

Hi.

The problems were there on the old battery - However you got me thinking - The speakers cutting out is following the new battery, and the front windows never faulted on the old battery - only the rear.

With the new battery both the front and rear windows fault - So the problems have got worse on the new battery.

I checked the voltage this morning after car sitting over night and read 12.38V. I believe this is undercharged so I am now leaning towards possible alternator problem despite the seemingly solid 14.4v when running.

My main concern is some vital electrical system shutting down whilst belting along the M4!

 

[whitenemesis]

Did your MB indie use STAR or a generic code reader?
I'd be surprised if there were no stored codes whatsoever...

 

[wongl]

Did you fully charge the new battery before you install it into your car?

 

[OneForTheRoad]

Hi.

The problems were there on the old battery - However you got me thinking - The speakers cutting out is following the new battery, and the front windows never faulted on the old battery - only the rear.

With the new battery both the front and rear windows fault - So the problems have got worse on the new battery.

I checked the voltage this morning after car sitting over night and read 12.38V. I believe this is undercharged so I am now leaning towards possible alternator problem despite the seemingly solid 14.4v when running.

My main concern is some vital electrical system shutting down whilst belting along the M4!

Have you re taught all the windows ?

 

[HairyBreeks]

Thanks all - In order -

Im not sure tbh which system he used, Ill revert back to him - he simply said no codes. I have now found a new specialist who definitely does have the STAR reader so that could be the next stop.

Whitenemesis - So are you saying it's likely that intermittent faults would leave some kind of code, even if the thing in question doesn't fault whilst the STAR machine plugged in? Thats actually the thing I really want to understand!

No I just installed the battery and had good starting power from the outset. I didn't think new batteries needed charging - just googled it - seems to split opinion that one! I've done some 3hr plus drives in last few days so would expect more that 12.38V reading in the morning?

Yes, the same 'no codes' mechanic did something with the windows to reset - no better.

Could a voltage regulator cause a load of weirdness like this?

Cheers

 

[whitenemesis]

Whitenemesis - So are you saying it's likely that intermittent faults would leave some kind of code, even if the thing in question doesn't fault whilst the STAR machine plugged in? Thats actually the thing I really want to understand!

Yes there will be a history of fault codes, even if those faults have 'corrected' themselves.
One of the first things a tech should do with STAR is to log then erase all error codes and then run the car to see which come back and are 'current'

 

[geoffus]

Just wondered if you have tried to reset the windows yourself lately ?
Its easy to do, and I wonder if the faults are connected.

 

[HairyBreeks]

Thanks for the info on STAR. This will be my next stop I think. Yes, I've done the window thing after the battery change due to one popping down, but they still get confused.

I'm now obsessing over the alternator output which I feel may be the problem as it never drops below 14.4v volts, often up to 14.9v, with the 'IB' amps reading on the hidden menu reading between 1-2 Amps. My understanding was the bluefficiency cars dropped the voltage when cruising, but mine never does this even over 4 hour drives. Hopefully the STAR diagnostics will throw some light on this.

 

[OneForTheRoad]

Thanks for the info on STAR. This will be my next stop I think. Yes, I've done the window thing after the battery change due to one popping down, but they still get confused.

I'm now obsessing over the alternator output which I feel may be the problem as it never drops below 14.4v volts, often up to 14.9v, with the 'IB' amps reading on the hidden menu reading between 1-2 Amps. My understanding was the bluefficiency cars dropped the voltage when cruising, but mine never does this even over 4 hour drives. Hopefully the STAR diagnostics will throw some light on this.

Your data card should show if its fitted with a high output alternator. Hence 14.9v

 

[Flyinspanner]

Initially do the window reset, you just use the door switches yourself. Look on you tube how to, dead easy.

 

[geoffus]

Just checked my voltage first thing -0.5 degrees this morning, 11-8 volts.


After starting and left running for a few minutes it went to 14.8 volts.


After switching off and resting it settled down to 12.5 volts, a new battery was fitted last week and it now starts every morning instantly.

 

[BlackC55]

The window runners on the 212 get tight and sometimes need a lube. This can make the windows activate the force limiter and not close on the one touch. Re-set the windows, use silicone spray on the runners and see how you get on.

The radio issue is probably down to a faulty head unit. Its difficult, almost impossible to diagnose as codes are not often left. Make sure a genuine battery is fitted. So many times we have seen the battery replaced with an incorrect one or one that is not as good quality as the genuine items. Genuine batteries are better as they are made to MB's spec and they will fit and be 100% correct if looked up properly. Poor battery voltage can cause the audio system to cut out.

Try your spare key and see how that works. The steering locks can cause issues on the 212 giving you this symptom also. Change your key batteries too. Don't buy cheap ones. Get branded quality items.