I took my 240D to the mechanic today. During the conversations about
racing, skydiving, NASCAR, etc., the comment "check engine" light came up.
What I learned was that when
you "over-fill" the fuel tank, (at least on the newer MBs) you will get that
"check engine" light.
He said that when pumping fuel, stop as soon as the pump kicks off. Because
a gadget that measures the amount of air(?), and fuel and when you keep
trying to put more fuel into it, you mess up that electronic gadget's
reading. So, he says to STOP PUMPING fuel as soon as the PUMP CLICKS OFF
and you will not get that (faulty) "check engine" light. He said he learned
that himself. Also several other 'goodies' but not pertaining to MB's.
You who are experiencing this "check engine" may want to observe this with
your vehicle, assuming that in reality you don't need to have the engine
No he didn't, and I didn't think to ask. I just assumed he drove it until
went off. He just said that he never did that again and never again had
the light come on. Just my two cents worth: Perhaps a sensitive electronic
sensor somewhere got blocked? I dunno. At work we have a copier that
often (after an ACTUAL paper jam) will continue to display the message that
there is a paper jam. Sometimes just 'going through the motions' (lifting
different lids, doors, drawers, etc., in sequence) will resolve it, but at
times it must have the power shut off for a few MINUTES for the memory
to be lost. Perhaps someone can reset - reprogram the electronic memory?
I don't know... sometimes automatic programming is difficult to erase.
I like the 240D!
To turn off the CE light, you need an OBD II code reader - It will tell you
which code caused the light to come on - If you are lucky, it could be the
gas filler cap, but it could also be any one of a number of other and more
complex problems - Bad Mass Air Flowmeter, bad Oxygen sensor and so on.
To get the code checked either go to your dealer (<$100) , or in the USA go
to one of the chains like Auto Zone or Pep Boys - they offer a free service
of checking the code and then zapping it (which the code reader can do). You
can also buy your own code reader for $100+.
You would need an OBD analogue code reader . All cars after 1988 would use
that system - From 1996 on they have OBD II which is digital.
A Google search should provide what you need. Here is one review:
An even simpler solution which works on my w124 ('95 e320te) is to simply
disconnect the negative battery cable for a few minutes (10 or so). Just be
sure that you have the radio security code handy- you will need enter it to
turn the radio back on.
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