3500 4x4 Pickup L6-359 5.9L DSL Turbo (1996)
Brake Fluid Pump Relay: Description and Operation
When the Controller Anti Lock Brake (CAB) grounds the ABS pump relay on circuit B116, the relay contacts CLOSE connecting circuit A10
from the Power Distribution Center (PDC) and circuit B120. Circuit A10 connects to fuse 5 in the PDC. Circuit A20 from the fuse 14 in the fuse
block splices to feed the coil side of the ABS warning lamp relay and the pump motor relay.
From the ABS pump relay, circuit B120 splices to supply voltage to the ABS pump motor and all solenoids in the hydraulic control unit. Circuit
B120 also supplies power to the solenoids in the Rear Wheel Anti Lock (RWAL) valve. Additionally, circuit B120 provides an input to cavity 34
of the CAB. The input tells the CAB that voltage has been supplied to the pump motor.