Antilock Brake System Automated Bleed Procedure Hybrid Vehicles

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

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

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. Refer to Tire and Wheel Removal and Installation .
3. Inspect the brake system for leaks and visual damage. Refer to Brake Fluid Loss or Symptoms - Hydraulic Brakes . Repair or replace as needed.
4. Inspect the battery state of charge. Refer to Battery Inspection/Test .
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 .
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.

•	If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding .

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 .
14. Inspect the brake fluid level. Refer to Master Cylinder Reservoir Filling .
15. Road test the vehicle while inspecting that the pedal remains high and firm.

Antilock Brake System Automated Bleed Procedure Non-Hybrid Vehicles

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

Important: 

The ABS Automated Bleed Procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge any air from the secondary circuits. These circuits are normally closed off, and are only opened during system initialization at vehicle start up and during ABS operation. The automated bleed procedure opens these secondary circuits and allows any air trapped in these circuits to flow out away from the brake modulator assembly, which is then forced out at the brake corners by the pressure bleeder.

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 and support the vehicle. Refer to Lifting and Jacking the Vehicle .
2. Remove the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
3. Inspect the brake system for leaks and visual damage. Refer to Symptoms - Hydraulic Brakes . Repair or replace components as needed.
4. Lower the vehicle.
5. Prepare the brake bleeding equipment and the vehicle for a pressure bleed of the base hydraulic brake system. Refer to Hydraulic Brake System Bleeding .
6. Inspect the battery state of charge. Refer to Battery Inspection/Test .
7. Install a scan tool.
8. Turn the ignition ON, with the engine OFF.
9. With the scan tool, perform the following steps:

9.1.	Select Diagnostics

9.2.	Select the appropriate vehicle information

9.3.	Select Chassis

9.4.	Select Electronic Brake Control Module (EBCM)

9.5.	Select Special Functions

9.6.	Select Automated Bleed

10. With an assistant ready, raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

Important: 

•	Apply the brake pedal when instructed, using moderate effort.

•	Ensure the pedal remains applied until instructed to release by the scan tool.

•	Do not exceed the time period allowed by the scan tool for having the bleeder valves open.

•	The bleed sequence for each corner is as follows:

-	Left front

-	Right front

-	Right rear

-

Left rear

11. Perform the automated bleed procedure as instructed by the scan tool.
12. If the automated bleed procedure is aborted, a malfunction exists. If a DTC is detected, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose the DTC.
13. After completion of the automated bleed procedure, press and hold the brake pedal to inspect for pedal firmness.
14. If the brake pedal feels spongy, repeat the bleed procedure completely.
15. Remove the scan tool.
16. Install the tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
17. Lower the vehicle.
18. Adjust the brake fluid level. Refer to Master Cylinder Reservoir Filling .
19. Road test the vehicle while confirming the brake pedal remains high and firm.