For 1990-2009 cars

The following procedure provides a complete Delco Bosch 5 brake system bleed. The procedure cycles the system valves and runs the pump in order to purge air from the secondary circuits. The secondary circuits are normally closed Off during non-ABS/TCS mode operation and bleeding. Use this procedure when it is suspected that air has been ingested into the secondary circuits, or after BPMV replacement.

1. Raise the vehicle. Support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove all four tire and wheel assemblies. Refer to Wheel Removal in Tires and Wheels.
3. Inspect the brake system for leaks. Refer to Brake Fluid Leak in Hydraulic Brakes.
4. Inspect the brake system for component damage. Refer to Brake System Testing in Hydraulic Brakes.
5. Inspect the battery state of charge. Refer to Battery Load Test in Engine Electrical.
6. Connect the scan tool to the DLC.
7. Turn the ignition to RUN. Do not start the engine.
8. Establish communications with the Scan Tool.
9. Select the ABS/TCS system features.
10. Select Special Functions.
11. Select Auto Bleed Procedure.
12. Bleed the base brake system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
13. Follow the scan tool driven instructions until the proper brake pedal height is achieved.
14. If any malfunctions are detected, the bleed procedure will be aborted:

• | If DTCs are present, the Scan Tool will display DTCs PRESENT or will list the DTCs, depending on when the DTCs were set.

• | DTCs can be cleared in the Trouble Codes mode. Refer to the appropriate DTC in order to clear the DTC.

• | If the test is aborted but no DTCs are listed, refer to Diagnostic System Check .

• | Correct all system malfunctions before attempting the bleed procedure again.

• | If a road test is required for diagnosis, and the brake pedal is spongy, perform a conventional brake bleed. Achieve a firm pedal before driving the vehicle.

15. When the auto bleed procedure is complete, perform the following steps:

• | Depress the brake pedal. The brake pedal should be high and firm.

• | If the pedal is not firm, inspect the brake system for conditions that might cause the condition. Refer to Brake System Testing in Hydraulic Brakes.

• | If the brake system is OK, and excess pedal travel persists, repeat the bleed procedure.

16. Disconnect the scan tool.
17. Install the tire and wheel assemblies. Refer to Wheel Installation in Tires and Wheels.
18. Inspect the brake fluid level and fill as necessary.
19. Road test the vehicle while making several ABS/TCS actuations in a suitable area. The brake pedal should remain high and firm throughout the test.