Engine light is on

I think that you will be ok. The cruise control on your vehicle is basically a software program. it just uses the Electronic Throttle Body to apply power to maintain a speed setting. Better to use the Engine to brake on a steep hill than to risk your life! You made the right decision!! Engine braking in a lower gear should be fine as long as you don't rev the motor up to say 5000 rpm, 2000-3000 and with an occasional burst around 4000 rpm should be fine, I do it myself, I drive a stick shift Camry and when I go up to the the Sierra Nevada Mts, I use the gears to help keep the speed safe on hills.