K 2500 Truck 4WD V6-262 4.3L (1988)
Antilock Brake Module: Description and Operation
Electronic Control Module (ECU)
The Electronic Control Unit (ECU) mounts to a bracket next to the master cylinder. It contains a microprocessor and the software for system operation.
During a severe brake application the ECU controls the Isolation/Dump Valve to prevent the rear wheels from locking up. The ECU receives input
signals from the Digital Ratio Adaptor Controller (DRAC), stop lamp switch and front axle switch.