Volvo Repair: 2000 Volvo V70 XC, 2000 volvo v70, mercedes 300 diesel


Question
My wife and I purchased a used 2000 V70 in April in Seattle.  My mechanic (for our 1984 Volvo 240, and 1985 Mercedes 300 diesel) performed the 105,000 miles service even though it had only 100,500 miles on it.  
We drove it all the way to Michigan and then to Rochester to give the car to our daughter.  After 4,000 miles of trouble free driving, I had the oil changed before we left for Seattle (home).  Now three months later, the service light came on first and then the check engine light also came on.
I know the car is not due for service, how can my daughter reset the service light?
I asked my daughter to make sure the gas cap is properly replaced.  She did that but the check engine light is still on.  My daughter is new to Rochester and has no relationship with any mechanic out there in Rochester.  The dealer told her it would be $98 to diagnose the check engine light.
Also, where can my daughter get a duplicate key and the radio code?
I am sorry for multiple questions and thank you for your help.


Answer
duplicate key you can get from Volvo dealer only  
radio code also from Volvo dealer  the service light is just to remind you  that you are due for oil change  if you don't reset every time the light when you do oil change it comes on but it will turn off after 1 min of driving to rest the light you will need special tool you can do that for free when you do next oil change at Volvo dealer they will turn the light for free it is  included in oil change .for the check engine light you need to pay those $98 to find out what fault code you have you have no choice it can be gas cap or some sensor in the engine .also did you replace timing belt and the tenssioner with the 105k service make sure you change the tenssioner with the timing belt if you don't it will brake make more damage to the  engine very important to do that