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I thought the Anti Locking Brake system (ABS) prevented the road wheels from locking up under braking, no matter the reason for the lock-up.

I've just seen the Greg Murphy advert that would suggest to me that the ABS is only activated if you stomp hard on the brake pedal.

So does that mean if you are braking normally and hit oil, ice or gravel, the ABS won't activate?

Surely preventing lock-up full stop is the objective, not just preventing lock-up during panic braking?

Andrew

From the "Ask Jack" archives - 21 October, 2010

The braking systems fitted to the modern fleet of vehicles are designed to carry out several important roles.

Firstly they must deliver the best braking force possible under normal driving conditions and they must also distribute the correct amount of braking force front to rear.

With all of these systems in place there are many occasions under reasonably hard or light braking that the wheels will not lock and the ABS will not be required to activate (it is basically on standby). However, the minute the wheel sensors detect a lock-up situation is imminent, the ABS system will activate immediately to stop this happening.

Under these conditions the braking system will provide the best braking force possible while continuing to allow the driver to retain steering control of the vehicle.

Without the ability to steer the car the driver will lose total control, this would happen if the front wheels were allowed to lock.

So in summary, you are correct, ABS is designed to operate under several different scenarios and conditions.

I guess the Greg Murphy advert is highlighting once such condition.