Perform a manual or pressure bleeding procedure. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes. If the desired brake pedal height results are not achieved, perform the auto bleed procedure below.

The auto bleed procedure is used on Delco Bosch 5.3 equipped vehicles. The procedure cycles the system valves and runs the pump in order to purge the air from the secondary circuits normally closed off during non ABS/TCS mode operation and bleeding. The auto 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 in General Information.
2. Remove all four tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
3. Inspect the brake system for leaks and visual damage. Refer to Brake Fluid Leak or Brake System Diagnosis in Hydraulic Brakes. Repair or replace as needed.
4. Inspect the battery state of charge. Refer to Battery Inspection/Test in Engine Electrical.
5. Install a scan tool.
6. Turn ON the ignition, with the engine OFF.
7. With the scan tool, establish communications with the ABS/TCS system. Select Special Functions from the ABS/TCS menu. Select Automated Bleed from the Special Functions menu.
8. Bleed the base brake system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
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/Type and diagnose the appropriate DTC.

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

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 in Tires and Wheels.
14. Inspect the brake fluid level. Refer to Master Cylinder Reservoir Filling in Hydraulic Brakes.
15. Road test the vehicle while inspecting that the pedal remains high and firm. Refer to Diagnostic Test Drive .