If it is just the pad wear sensor then you can reset it the same way you reset the service indicators, no scan tool required. The procedure is as follows: (There is also a video on YouTube of the reset procedure)
1) Insert key
2) Press start button but do not press brake.
3) Wail for the chimes and lights to stop (about 5-10 seconds)
4) Press and hold odometer reset button until the service icons come up (about 10 seconds)
5) Scroll through the different service icons with the thumb wheel on the turn signal stalk until you get to the brake wear indicator.
6) Use the push button on the end of the stalk to reset the indicator.
*If the brake wear sensor circuit is open, you won't be able to reset it until you either replace the sensor or join the wires together.
If your ABS wheel speed sensor is the issue then you will indeed need a scan tool to reset
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