Chevrolet Equinox Service Manual: Antilock Brake System Automated Bleed Dynamics Control ABS Control

Warning:Refer toBrake Fluid Irritant Warning.

Caution:Refer toBrake Fluid Effects on Paint and Electrical Components Caution.

Note:Before performing the antilock brake system (ABS) AutomatedBleed Procedure, first perform a manual or pressure bleed of thebase brake system. Refer toHydraulic Brake System Bleeding. The automated bleedprocedure is recommended when one of the following conditionsexist:

Base brake system bleeding does not achieve the desired pedalheight or feelExtreme loss of brake fluid has occurredAir ingestion is suspected in the secondary circuits of thebrake modulator assembly

The ABS Automated Bleed Procedure uses a scan tool to cyclethe system solenoid valves and run the pump in order to purge anyair from the secondary circuits. These circuits are normally closedoff, and are only opened during system initialization at vehiclestart up and during ABS operation. The automated bleed procedureopens these secondary circuits and allows any air trapped in thesecircuits to flow out toward the brake corners.

Automated Bleed Procedure

Caution:The Auto Bleed Procedure may be terminated at any time duringthe process by pressing the EXIT button. No further Scan Toolprompts pertaining to the Auto Bleed procedure will be given. Afterexiting the bleed procedure, relieve bleed pressure and disconnectbleed equipment per manufacturers instructions. Failure to properlyrelieve pressure may result in spilled brake fluid causing damageto components and painted surfaces.

Raise and support the vehicle. Refer toLifting and Jacking the Vehicle.Remove all 4-tire and wheel assemblies. Refer toTire and Wheel Removal and Installation.Inspect the brake system for leaks and visual damage. RefertoSymptoms - Hydraulic Brakes. Repair or replacecomponents as needed.Lower the vehicle.Inspect the battery state of charge. Refer toBattery Inspection/Test.Install a scan tool.Turn the ignition ON, with the engine OFF.With the scan tool, establish communications with the ABSsystem. Select Special Functions. Select Automated Bleed from theSpecial Functions menu.Raise and support the vehicle. Refer toLifting and Jacking the Vehicle.Following the directions given on the scan tool, pressurebleed the base brake system. Refer toHydraulic Brake System Bleeding.Follow the scan tool directions until the desired brake pedalheight is achieved.If the bleed procedure is aborted, a malfunction exists.Perform the following steps before resuming the bleedprocedure:If a DTC is detected, refer toDiagnostic Trouble Code (DTC) List - Vehicleand diagnose the appropriateDTC.If the brake pedal feels spongy, perform the conventionalbrake bleed procedure again. Refer toHydraulic Brake System Bleeding.When the desired pedal height is achieved, press the brakepedal to inspect for firmness.Lower the vehicle.Remove the scan tool.Install the tire and wheel assemblies. Refer toTire and Wheel Removal and Installation.Inspect the brake fluid level. Refer toMaster Cylinder Reservoir Filling.Road test the vehicle while inspecting that the pedal remainshigh and firm.