94 Volvo 850 check engine light

Hello,
I have a '94 850 nonturbo. Im wondering if the check engine light is a
smart system in that if it doesnt sence the failure in xx amount of starts
the light will go off?

I pulled my airfilter box top off and started the car, and I believe the
airflow meter signaled that no air was flowing over it while the car was
started so it triggered the check engine light. But will it go off (since
theres nothing wrong with it) after say 25 starts with no problem or must I
take it to the dealer to have it reset?

Thanks,

 

i think the early 90's volvo warning systems do re cycle
themselves after a certain number of starts or cycles...

do you have the little, black, circular rubber plug in the
"glass" of the insturment cluster? if so, pop it out and
press w/a pencil the button...while going from key out,
to insert key, start motor...shut off motor, remove key...
see what that does......

 

Is that not how you clear the "SER-VICE" light that comes up when you need
an oil change/routine service based on KM's traveled? Or does it shut off
both?

 

My 94 doesnt have this on the dash, so I guess I'll just drive it around for
a month or so and see if the light eventually goes off, may take a month if
the auto reset is set high enough since I dont drive it all that often.

 

Try disconnecting the battery for 5 minutes... works a treat on 99 S70's...

 

Make sure you have your radio code handy.

 

It will eventually turn itself off, assuming that there's no problem
remaining. However, you can do it yourself easily:

http://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm

Even though that's written for the 700/900, it's the same for your 850.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Thanks, I ended up taking it into the dealer because it started running
really bad, like it was missing on cylinders. The short whole story goes
like this:

I was cleaning the engine because the oil filler cap had been leaking for a
while so I used som gunk and a toothbrush, then hosed it off.

I then went to start the car and take it out for a drive to heat up the
motor to dry off any water. And when I started it, the car felt stumbly and
running on not all cylinders. After driving it a short while it cleared up
and seemed fine. I returned home and left the car till it was time to go to
dinner, then the car wouldnt start. I pulled the air filter hose off so it
was getting unmetered and unfiltered air, and after about 30 different
attempts to start it started, couple times putting it in gear and it died,
then it finally held an idle and was fine that night. Next day coming home
from shopping and it started to run bad again and felt like it wasn't on all
cylinders so I dropped it at the dealer. They called and said that it's
stored a couple codes, unmetered air leak and a couple sensor codes
(probably water, though I dont know why it would run fine the day that I
took it into the dealer, but then later that afternoon start running bad
again).

Anyway, they say it should be fixed tomorrow so we'll see what happens.

Thanks,

 

Ahhh, yes, nothing like the whole story. Those engines do that when
washed - they're OK, then they're not. Water can get in the distributor
cap, so removing that and drying it out is the first step. (This is
really easy if you remove the airbox first.) Second is water can get
into the spark plug wells - remove the plastic cap on top of the engine
(6 torx screws) and pull the wires off the plugs, and dry out the spark
plug wells and wire ends.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)