W220 S320CDI Engine Management Light Conundrum..

[markben]

Greetings all

I know many posts around problems with EMILs (Engine Management Indicator Light) focus on the light staying ON. But has anyone here experienced the following:

My 'S' has just failed an MOT at a 'fast-fit' (or similar) outlet due to the orange EMIL NOT coming on (aside from a couple of minor suspension faults - a separate issue). The tester says it should come on briefly, then extinguish (as is usual for most cars): and so referred me to an auto electrician who took the speedo assembly out and discovered.. wait for it... NO bulb or LED for the EMIL. (BTW: 2004 model S320L CDI, 120k miles, very solid service history, runs perfectly, smoke free, emissions good, 45 mpg on a run).

Auto electrician says, after some research, that certain models of Diesel S Class (2003 -2008) 'q' "do not have provision for the usual orange dash light since any EM-related issue will be displayed via the On board Computer fault warning display in the centre of the instrument panel". Second MOT (by mate of auto electrician) - no mention of EMIL issue. £130 for the privilege... ouch.

Back to the fast fit centre with my concerns: they stand their ground and dispute the auto electrician's / other MOT tester's verdict saying 'we too have checked the VOSA (now DVSA) technical data' and are following the Rules by failing the car due to no EMIL'. They say I can appeal to the DVSA against their opinion - but the process seems pretty long-winded.

So, my Question: should (or should not) the EMIL light on my car function - or not...?

Technical answers / suggestions on a postcard please....?

Many thanks

MB (Bristol area)

 

[Steve@Avantgarde]

All S Classes have an EML light that is part of the printed circuit board and not illuminated by a bulb, I think.

At ign position 2 all of the dash lights should come on to self test, then the ones which are used for warning systems, such as EML, SRS, ABS/ESP should turn off after 5 seconds or as you crank the engine.

I know on some MB's it was possible to code out the engine light as in some countries you don't need it.

The best thing to do is scan it with STAR, see if there is any hard faults in the EML which would be worthy of turning on the EML light, if not, then you need to look at the cluster as the possible cause.

You aren't far from me so if you wanted me to cast an eye, then get in touch.

 

[markben]

All S Classes have an EML light that is part of the printed circuit board and not illuminated by a bulb, I think.

At ign position 2 all of the dash lights should come on to self test, then the ones which are used for warning systems, such as EML, SRS, ABS/ESP should turn off after 5 seconds or as you crank the engine.

I know on some MB's it was possible to code out the engine light as in some countries you don't need it.

The best thing to do is scan it with STAR, see if there is any hard faults in the EML which would be worthy of turning on the EML light, if not, then you need to look at the cluster as the possible cause.

You aren't far from me so if you wanted me to cast an eye, then get in touch.

------------------

Many thanks Steve. On further research (with DVSA and 2 local Indies) it appears that the new 2018 MOT testing provisions don't mention the need to test the MIL light for diesels between 2003 and 2008 - only petrol engines. So, it seems that my local fast fit have made an error - regardless. But they aren't holding their hands up until they've done their own checks. I'll keep you posted either way..

Thanks again

MB

 

[4lch3my]

I had the same issue on my 2004 w220 and after doing some checks online and then taking it to another local garage it passed fine so I think it is just down to your luck really.

 

[markben]

I had the same issue on my 2004 w220 and after doing some checks online and then taking it to another local garage it passed fine so I think it is just down to your luck really.

It turns out that under the recent new (May 2018) MOT testing criteria for 'Engine Malfunction Indicator Light', at the time of testing there was NO requirement to check this on diesels. See Section 8.2.2. in the MOT testers' guide. My fast fit centre eventually confirmed their error in failing the car on something which was not necessary to check. Yep, a further MOT with the garage who supplied the car confirmed this and it passed, no problem. It seems that the new MOT rules are creating quite a lot of confusion for both Testers and Customers, and the DVSA is continually releasing updates for MOT testers....