Antilock Brake System Automated Bleed Procedure

Antilock Brake System Automated Bleed Procedure

Bleeding the ABS System

Caution: Refer to Brake Fluid Irritant Caution.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice.

Perform a manual or pressure bleeding procedure. Refer to Hydraulic Brake System Bleeding (Manual) 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

Notice: 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. Raise the vehicle on a suitable support. Refer to Lifting and Jacking the Vehicle.
2. Remove all four tire and wheel assemblies.
3. Inspect the brake system for leaks and visual damage. Refer to Brake Fluid Loss or Symptoms - Hydraulic Brakes. Repair or replace as needed. Brake Fluid Loss Symptoms - Hydraulic Brakes
4. Inspect the battery state of charge.
5. Install a scan tool.
6. Turn ON the ignition, with the engine OFF.
7. With the scan tool, establish communications with the 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 (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 Trouble Code (DTC) List - Vehicle , to diagnose the appropriate DTC. Diagnostic Trouble Code Descriptions
* If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding (Manual) 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.
14. Inspect the brake fluid level.
15. Road test the vehicle while inspecting that the pedal remains high and firm.