Check Engine light comes on 3-5 seconds after start. Have had it
checked, and re-checked, Volvo shop says it shows no codes, nothing
is wrong, but they can't reset it. They say it's a recurrent problem
with mid 90's Volvo 850s. Have had all scheduled maint., and oil changes
every 2500 miles (recommended to me because of the turbo).
Seems to be running just fine!
Is there any way I can reset the code?
Thanks!

VELLIS,

YOUR PROBLEM COULD BE AS SIMPLE AS RESCREWING YOUR GAS CAP OR REPLACING IT COMPLETELY. I HAD THIS SAME PROBLEM WHEN MY '97 850 WAS LESS THAN A YEAR OLD AND IT TURNED OUT TO BE A DEFECTIVE GASCAP. HOWEVER, A LOOSE GAS CAP COULD EASILY SET OFF THAT ANNOYING LIGHT.

GOOD LUCK!!

No trans code either? A trans code can trigger a check engine light.

You can try a used ECU if nothing else to see if that's possibly your problem. The reason why you might not be able to do what someone else has suggested, putting tape over the light is because in some states now, like mine, they test all '95 on up cars by using a scan tool only so if the light's on, I'm sure they'll fail you until it's fixed.

If you're having a dealer look at this, ask them if they'd try another used ECU from another '95 850? It's very easy and I've done that at times as it'll take further guesswork out of it and no parts department wants techs or customers returning costly SOP electrical parts either. There's no way any tech can test a ECU as all Volvos diagnostics test everything but, then one's left to assume it's an ECU problem. They're not that expensive when found used, a fraction of new part cost.

Earl,
I bet they didnt check for transmission codes, if they did they didnt
say anything to me about it..and thats a good idea, because the light
came on after I'd switched from 'sport' to 'winter' while trying to
go up an icy hill, the trans 'up' light came on and went out, then the
check engine light. didnt even think about that, I'll do what you
suggested. thanks much!!!!!

It is a waist of money to change your oil every 2500 miles...

You can change it every 6000 or 5000 not 2500.. oil now day are good and not brake down easy... Don't waist your $$$$$$$


as for the code.. yes what happend it your ECC computure have a glish or going bad but nothing wrong with the car so why worried ?????

to change that computure will cost you $1500 plus labor Do you realy want to do
that ??? just because of the light check ????

NO.. stop taking it to the dealer for every little thing this car will make you go broke at no time ...ignore the problem run ...

1 per month check the code by yourself .. Try disconnect the battery for 15 minutes than reconnected and clear the code may be it will help..

do you know how to clear the code ?? if not go to www.volvospeed.com it show you all the detail how to read and clear the code..

I can not clear mine for long time about 3 month than 1 day I did it and it clear .... enjoy the car and stop take it to the shop ..

850 every one know it a lemon with many little bug and problem... but all that we can live with .... I have my check light go on every week.. hey just put a small piece of black tape over the light .. good luck...

thanks for the URL, I printed out the clear procedures and hopefully
they'll work. I'm only concerned about the CE light being on because
I'm thinking of selling the car to get something smaller, I've moved
to where i'm less than 2 miles from work and will ride bike during the
summer. and the oil change thing is what the mechanic said because of
the turbo, which he said goes out usually about 75k miles..and when i
bought the car it had 69k so I was scared. thanks for your advice and
the url!!!!!!