First perform a manual or pressure bleeding procedure. Refer to Pressure 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 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.

Items Required

Auto 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.
2. Remove all four tire and wheel assemblies.
3. Inspect the brake system for the following conditions. Repair or replace as needed:

•

Leaks

•	Visual damage

4. Inspect the battery state of charge.
5. Connect the scan tool to the DLC.
6. Turn the ignition to ON position with the engine off.
7. Using the scan tool, establish communications with the ABS/TCS system.

Select the following features:

•

ABS/TCS

•	Special Functions

•	AUTOMATED BLEED PROCEDURE

8. Bleed the basic brake system. Refer to Pressure 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 the appropriate DTC table.

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

11. When the desired pedal height is achieved, press the brake pedal in order to inspect for firmness.
12. Disconnect the scan tool.
13. Install the tire and wheel assemblies.
14. Inspect the brake fluid level.
15. Road test the vehicle while making sure the brake pedal remains high and firm.