The ABS Automated Bleed Procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge any air from the secondary circuits. These circuits are normally closed off, and are only opened during system initialization at vehicle start up and during ABS operation. The automated bleed procedure opens these secondary circuits and allows any air trapped in these circuits to flow out toward the brake corners.
- Before servicing the vehicle, refer to the Precautions Section.
- Raise and support the vehicle.
- Remove all four tire and wheel assemblies.
- Inspect the brake system for leaks and visual damage.
- Inspect the battery state of charge.
- Install a scan tool.
- Turn the ignition ON, with the engine OFF.
- With the scan tool, establish communications with the ABS system. Select Special Functions. Select Automated Bleed from the Special Functions menu.
- Following the directions given on the scan tool, pressure bleed the base brake system.
- 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:
If a DTC is detected, diagnose the appropriate DTC.
- When the desired pedal height is achieved, press the brake pedal to inspect for firmness.
- Remove the scan tool.
- Install the tire and wheel assemblies.
- Inspect the brake fluid level.
- Lower the vehicle.
- Road test the vehicle while inspecting that the pedal remains high and firm.