why is abs light on?

Hello, Most often the ABS light comes on when one of the wheel speed sensors is damaged or defective, however, there are very many issues that will illuminate the ABS light, and testing will need to be conducted. You can scan the vehicle for OBD trouble codes at many auto parts stores for free. You can post those codes here for additional assistance, or see one of the certified shops in your area by viewing the list here: http://repairpal.com/infiniti-within-10-miles-of-bennington-vermont-05201