The Service Reset light comes on at regular mileage points to alert you to perform
necessary maintenance to keep your Volvo 850 running properly.
When you do the work yourself the light can be reset with these instructions.
Volvo 850 (1993-1995) Service Light Reset
Under the hood there are 2 diagnostic units (labeled A and B on the cover) next to the washer reservoir.
1. Turn on the ignition and open diagnostic unit A.
2. Locate the flylead (the test wire that is in the plastic holder).
3. Insert the flylead into socket 7.
4. Press the large round test button on the diagnostic unit 4 times, briefly but firmly.
5. When the LED flashes and then stays lit, it will accept the reset code.
6. The reset code for the service light is 1-5-1.
7. Press the large round test button firmly one time and then release it. The LED should be lit.
8. Press the button firmly 5 times and then release it. The LED should be lit.
9. Press the button firmly one more time and then release it. The LED will flash several times.
10. Turn off the ignition switch and replace the flylead in its holder and close the cover.
The Service Light has now been reset.
Volvo 850 (1996-1997)
You need the OBD II reset tool. The price is approx. $150.
Or take your car to a Volvo dealership or an independent Volvo shop.
Expect to pay $50-$75.