Re: How to reset O2 sensor light in 1988 528e?

["J. Cash" <j.cash@xxxxxxxxxxxx>]

Tom Borden writes



Hey All,



I have heard along the way that there is a switch that needs to be thrown to
kill the incessant O2 Sensor warning light in my overhead console.  Does
anybody know where this switch is and/or what's required to reset it?



Thanks very much.



Tom

An initial response to this message stated that there was no O2 warning
light in the overhead console.



Wellll - that my be possible on the 88 car, but since Tom specifically
mentions it, I suspect the 88 version is similar to my 82 528e - in that
"Check Control Display Panel" is overhead (above the mirror) and that it
does include a message lamp for the O2 sensor.



If that is the case, then the operation of the warning lamp "might" be the
same as the 82 version (although that may have changed even if the position
of the warning lamp did not).



On the 82 car the O2 sensor warning light was strictly controlled by a
mileage factor. When the odometer rolled past a certain number of miles
(30,000? - can't remember) it caused a contact to make and that caused a
small fuse to blow in the rear of the instrument cluster. To reset the
warning lamp they had to replace that fuse. I am not sure about this but I
seem to remember that it would only operate the first time, and that after
the first reset the lamp would never come on again.



Again I am going by memory - but look at the back of the cluster (directly
behind the speedometer) and see if there is a small cover that can be
removed - if so, and if there is a small fuse in there pull it out and
replace.



Note - the memory of this is now about 18 years old - so allow for some
measure of error.



Of interest - I never did replace the O2 sensor on that car in 14 years and
300,000 kms of operation. All I did was remove it yearly and make sure the
slots were clear of any exhaust residue. This was a bit heavy in the early
years but later (after fuels were revamped in the later 80's) it stayed much
cleaner. I was always able to pass the O2 emissions tests - dealer did an O2
calibration on the AFM several times and always found it to be OK.



Cheers

Jim Cash

[demime 0.99c.7 removed an attachment of type image/jpeg which had a name of image001.jpg]

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