Brake Signal: Description and Operation

PURPOSE/OPERATION
The anti-lock braking signal is input to the engine control module from the Anti-lock Braking System (ABS) control unit as a signal to indicate whether or not the motor relay is activated. Based on this signal, the engine control module controls the idle air control motor to secure effective anti-lock braking. When the motor relay is activated, the ABS control unit turns ON the power transistor, short-circuiting the terminal to ground. This causes the anti-lock braking signal to go from high to low.