car is traveling at middle speed or high speed there is a frequent vibration
on the car body, the steering wheel and the brake pedal when the brake pedal is
depressed lightly. The vibration will disappear when the brake pedal is
released, it means the brake judder, also called as brake shimmy by some. This
is cause by a certain speed regardless where the gear is positioned and the
speed of the engine.
Why is the anti lock brake light on? Well if the abs light came on it means that there is a fault somewhere in the anti-lock brake system. But if the ABS light came on for a couple of seconds when the engine is started then this is normal, it indicates of the self-test of the system.
What would cause an engine to lose power? If an engine lose power especially those of low mileage car is cause by a fault in the ignition system or fuel system. Observing the engine behavior will point out to the exact problem, like for example if the engine is rough on idle it means that the spark plug or the spark plug wires is bad.