W203. New Year,New Niggle!

[Paul Goff]

Yesterday my 2002 W203 CDi220 threw it's auxiliary drive belt, no big problem, I put a new one on, checked it visually while running and tested the charge voltage with everything switched on. All OK

BUT the big red warning message on the display won't reset!

My owners manual makes it clear that I should be able to reset it and says how to do so, however the car has other ideas, so I haven't been able to do this.

Did a search here, and it seems that disconnecting the battery for a couple minutes could clear it. That's fine, can do that but am a bit wary of stirring up other problems with modules etc if I do, or do so incorrectly!

Is it better to just leave it, or disconnect away? If the latter, is there a specific procedure other than the usual negative off first/back on last?

 

[malcolm E53 AMG]

Try running the car as is sometimes these things reset after a number of starts, if it doesn’t disconnect the battery as you describe or use STAR

 

[LostKiwi]

As Malcolm says... Sometimes after 3 'long' starts the light will reset.
A long start is where the car gets to temperature and covers a certain distance (couple of miles) with no further occurrence.

 

[Paul Goff]

Thank you chaps, I will leave it as is for a few days use, if it clears the warning then that is good enough for me.

 

[Steve@Avantgarde]

There is a signal wire that goes to the alternator that always breaks and puts on the alternator light.

 

[Paul Goff]

There is a signal wire that goes to the alternator that always breaks and puts on the alternator light.

Hi Steve, Thanks for the info, is this the Blue 0.75mm cable that connects Term1 on the alternator to connector18 pin2 for the electronic doodah in the engine fuse box? (according to that great tome of mystery and imagination, the Haynes Manual ) Is it likely that my Aux belt failure might have broken it, or would it, if it is broken somewhere, just be a coincidence?

 

[Steve@Avantgarde]

Thats the one! They usually break Paul, it could have been taken out by the belt, without seeing it its hard to say.

 

[Paul Goff]

Thats the one! They usually break Paul, it could have been taken out by the belt, without seeing it its hard to say.

Cheers, I will keep my fingers crossed that it clears itself some time soon, don't fancy my chances of even seeing it at the alternator end, even less doing anything with it

 

[Paul Goff]

IT'S ONLY GONE AND GORN

Left it for a week of normal use, however many Short or Long starts that may be, and was greeted by the red warning every time I went anywhere!

So I have just disconnected the negative from the battery for however long it took to NoCorrode the post and the clamp, put it back and that has cleared the fault display

And as far as I can tell it hasn't affected anything else, he said foolishly!

Thank you all for the input.

Goffy.