Bleeding the ABS/TCS System
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 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/ICCS
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.
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.
- Raise the vehicle on a suitable support. Refer to
Lifting and Jacking the Vehicle
in General Information.
- Remove all four tire and wheel assemblies. Refer to
Tire and Wheel Removal and Installation
in Tires
and Wheels.
- 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.
- Inspect the battery state of charge. Refer to
Battery Check
in Engine Electrical.
- Connect the scan tool to the data link connector (DLC).
- Turn the ignition switch to ON position, engine off.
- Use the scan tool in order to establish communications with the
ABS/TCS/ICCS system. Select Special Functions from the ABS/TCS/ICCS menu.
Select Automated Bleed from the Special Functions menu.
- Bleed the basic brake system. Refer to
Hydraulic Brake System Bleeding
in Hydraulic Brakes.
- Follow the scan tool directions until the desired brake pedal
height is achieved.
- If the bleed procedure is aborted, a malfunction exists. Perform
the following steps before resuming the bleed procedure:
- When the desired pedal height is achieved, press the brake pedal
in order to inspect for firmness.
- Disconnect the scan tool.
- Install the tire and wheel assemblies. Refer to
Tire and Wheel Removal and Installation
in Tires
and Wheels.
- Inspect the brake fluid level. Refer to
Master Cylinder Reservoir Filling
in Hydraulic Brakes.
- Road test the vehicle while inspecting that the pedal remains
high and firm. Refer to
Diagnostic Test Drive
.