Slip Indicator Light

Very simply the 'Slip Indicator Light' has been going on more and more  lately. At first it was once or twice when leaving my garage in the ramp  or off the highway on a sharp turn and funny hill. I thought oh it's  just cause the wheels are a bit heavy and it's a strange hill, turn. 

But now it's progressed and I think it could be a bigger problem. I am  Getting it allot more. It's the rear wheels and now it at times happens  when on a hill going upwards. Does not seem right. It's not snowing  lol!! It's not wet. But the wheels are heavy. 21"s and allot wider than  stock as well. Could it be over time some parts are giving and not being  able to rotate the wheels? So strange to me.

Any suggestions wold be great. On Air bags. AccuAir also and it's an AWD. Some one on another thread mentioned cleaning the wheel sensors real good on the hubs?

Also a certified Toyota tech told me it should be the ride height sensor that needs to be recalibrated.

wheel slip is usually calculated by wheel speed sensors. ride height normally doesn't have anything to do with wheel slip.

My guess is you've got some pretty caked up Sensors and they're having a hard time picking up the notches in the rings to monitor wheel speed.

Makes sense to me and from what another person also said on club Lexus. So I have to replace the rotors next week. I am gonna clean them then. I will let you know the results after a weeks or so on the daily. Thanks :)

So far what my mechanic told me was that my rotors were warped and that is sets off this kind of issue because they are lose and uneven. My front pass. side rotor was crystallized and you could see the damage in the back. Also my rear brakes were done. So I have been using the front brakes mostly and on warped rotors. 

Did the switch today to slotted and drilled front and rear. New brakes. I hope that's it. I will check in in a few days to see cause I should know since it happened enough where it should not happen at all now.