having a little problem with my service soon light in my 98 volvo s90, what it is don't no how to cut it off after service and also having problems cutting off the check engine light as well, i have disconnect the battery an it went off for about ten minutes an back on, now i did put some 87 gas in it an it came on but have put 89 r 91 in it but the light still stays on so if anyone can give me some pointer on how to cut both lights off i would appreciate it Thanks

 

You need to fix whatever problem is causing the check engine light.

 

I have an S70, but on the 98 S70, you can't turn off the service light no matter what you do. It goes out on its own every day after 2 minutes. I can live with it. I don't know about the S90.