For 1990-2009 cars

First 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 procedure cycles the system valves and runs the pump in order to purge the air from the secondary circuits. These circuits are normally closed off during non-ABS mode operation and bleeding. Perform the auto-bleed procedure when you suspect air ingestion in the secondary circuits, or when you replace the BPMV.

#### Items Required

• | A scan tool

• | A 30-psi adapter equipped brake bleeder

• | Delco Supreme 11 brake fluid

• | A hoist

• | An unbreakable plastic bleeder bottle equipped with a hose

• | An assistant

• | Suitable safety attire, including safety glasses

### 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. Refer to Lifting and Jacking the Vehicle in General Information.
2. Inspect the brake system for leaks and for visual damage. Repair or replace as needed.
3. Inspect the battery state of charge.
4. Connect the scan tool to the DLC.
5. Turn the ignition to the ON position with the engine off.
6. Using the scan tool, establish communications with the ABS system.

Select the following features:

• | Special Functions

• | AUTOMATED BLEED PROCEDURE

7. Bleed the base brake system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
8. Follow the scan tool directions until you have achieved the desired brake pedal height.
9. 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.

• | Perform the conventional brake bleed procedure again. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.

10. Perform base brake bleed procedure again. Repeat the Auto Bleed Procedure if proper pedal height is not achieved.
11. Disconnect the scan tool.
12. Inspect the brake fluid level. Add brake fluid if necessary.
13. Road test the vehicle while making sure the brake pedal remains high and firm.