Antilock Brake System Automated Bleed

Antilock Brake System Automated Bleed

Bleeding the ABS System

Perform a manual or pressure bleeding procedure. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Manual)Hydraulic Brake System Bleeding (Pressure) Hydraulic Brake System Bleeding (Pressure). If the desired brake pedal height results are not achieved, perform the automated bleed procedure below.

The procedure cycles the system valves and runs the pump in order to purge the air from the secondary circuits normally closed off during normal base brake operation and bleeding. The automated bleed procedure is recommended when air ingestion is suspected in the secondary circuits, or when the BPMV has been replaced.

Automated Bleed Procedure

Caution:
The Auto Bleed Procedure may be terminated at any time during the process by pressing the EXIT button. No further Scan Tool prompts pertaining to the Auto Bleed procedure will be given. After exiting the bleed procedure, relieve bleed pressure and disconnect bleed equipment per manufacturers instructions. Failure to properly relieve pressure may result in spilled brake fluid causing damage to components and painted surfaces.

1. Inspect the battery state of charge. Refer to Battery Inspection/Test Battery Inspection/Test.

2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle Service and Repair.

3. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation Service and Repair.

4. Inspect the brake system for leaks and visual damage. Refer to Brake Fluid Loss Brake Fluid Loss or Symptoms - Hydraulic Brakes Symptoms - Hydraulic Brakes. Repair or replace as needed.

5. Install a scan tool.

6. Turn ON the ignition, with the engine OFF.

7. With the scan tool, establish communications with the electronic brake control module (EBCM). Select Special Functions. Select Automated Bleed from the Special Functions menu.

8. Bleed the base brake system. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Manual)Hydraulic Brake System Bleeding (Pressure) Hydraulic Brake System Bleeding (Pressure).

9. Follow the scan tool directions until the desired brake pedal height is achieved.

10. If the bleed procedure is aborted, a malfunction exists. Perform the following steps before resuming the bleed procedure:

* If a DTC is detected, refer to Diagnostic Starting Point - Vehicle Diagnostic Starting Point - Vehicle.

* If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding (Manual) Hydraulic Brake System Bleeding (Manual)Hydraulic Brake System Bleeding (Pressure) Hydraulic Brake System Bleeding (Pressure).

11. When the desired pedal height is achieved, press the brake pedal in order to inspect for firmness.

12. Remove the scan tool.

13. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation Service and Repair.

14. Inspect the brake fluid level. Refer to Master Cylinder Reservoir Filling Master Cylinder Reservoir Filling.

15. Road test the vehicle while inspecting that the pedal remains high and firm.