Brake Fluid Pump: Description and Operation

Fig 2 Hydraulic Control Unit Component Locations:

OPERATION
The pump/motor assembly consists of an electric motor with a rotation sensor and a dual piston pump. The rotation sensor is an inductive pickup used by the Controller, Antilock Brake (CAB) to monitor pump/motor operation.

Power for the Anti-Lock Brake (ABS) pump motor is supplied on circuit B82 from the ABS pump motor relay. This circuit is HOT when the contacts in the relay are CLOSED.

Ground for the motor is supplied on circuit Z1. This circuit terminates at the left front frame rail.

On vehicle equipped with the optional traction control there are two additional circuits that provide an input to the ABS control module. These circuits are B28 and B29 and are a twisted pair.