The front brakes have a separate sensor which needs to be replaced when you replace the brake pads. You must have seen a wire going to the brake pads when you replaced them. There is a sensor which plugs into the brake pads and plugs into the wire. If there is any break in the circuit (such as brake pads which have worn out the sensor wire, or if the sensor is missing), the light will come on. I once just cut off and twisted the wires together as a temporary fix.
The coolant level sensor in the overflow tank may be inoperative. You usually have to replace the entire coolant tank (I got one at foleyparts
caddyparts@gmail.com) for $64 plus shipping). Some folks have been able to fix the sensor without replacing the tank.
Barry