I just picked up a used "99" S70 T-5. Every time I start the vehicle the Service light stays on for ~5 mins, then goes out. Is this an indication of a malfunction or is it normal?

Use this method: turn the key to the run, (II) position. Push in the odometer reset button and hold it in. Turn key off and then back on, still holding down the odometer reset button. In a few seconds the service light will begin to flash. When it does, release the odometer button, and turn off the key. The light will be reset and won't come on again for another 7500 miles. This method doesn't work on '98's, I'm told, but it does on my '99.

There is a combination of actions with the ignition key and the tripmeter reset button that will reset the service light on the 2000 series S70 - I believe the 1999's are stuck using a tool.

MAT

Normal. This light is to indicate when the interval for an oil change has arrived. Unfortunately, in the 98-00 S/V/C70's you need a $200 device to reset the light...or your tech has to have the tool. In my case, the light has become invisible to me (I do my oil changes on time but the place where I get the changes done doesn't have the tool.) If I ever have to get to the instrument panel for any other reason, I'm going to remove the bulb.
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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)

I have a 1998 S70 and assume our circumstances are the same. My service light came on and was reset by the dealer during a maintenance visit. However, I checked about reseting the light with www.AllDataDIY.com, a web-based site with on-line maintenance information (for a fee). Though their information was initially incorrect, they sent me updated stuff that may work for you. They say (per a copyrighted Volvo bulletin) that the Service Indicator can be reset with the following procedure (parenthetical fragments are my guesses as to what Volvo meant):

1. (Start with) ignition off
2. Press in the trip odometer reset button (and hold)
3. Switch on ignition
4. Continue pressing in the reset button for 10 seconds
5. Release the reset button within 4 seconds (after light goes off)

If you still have your light on, try this with some variations to see if it works. I would appreciate a response about your success or failure, since I cannot test this procedure for quite a while.

Gene

ggrunby@yahoo.com