Auto Bleed Procedure
NOTE:
Auto bleed procedure is used to provide a complete bleed procedure on ABS/TCS equipped vehicles. This procedure cycles system valves and runs pump to purge air from circuits normally closed during non-ABS/TCS (normal) brake system operation and bleeding. This procedure should be used when air is suspected in secondary circuits or when Brake Pressure Modulator Valve (BPMV) assembly has been replaced.
CAUTION:
Perform MANUAL BLEEDING PROCEDURE or PRESSURE BLEEDING PROCEDURE before performing auto bleed procedure.
- Raise and support vehicle. Remove wheels. Inspect brake system for leaks or damage. Repair as necessary before continuing.
- Ensure battery is fully charged and connect pressure bleeding tool at 30-35 psi (2.12-2.47 kg/cm2 ). Connect scan tool to Data Link Connector (DLC) located under left side of instrument panel. Turn ignition on, with engine off. Using scan tool, select ABS/TCS system features. Select SPECIAL TESTS and then select AUTOMATED BLEED PROCEDURE.
- Follow scan tool menu-driven instructions until proper brake pedal height is achieved. If malfunctions are detected, bleeding procedure will be aborted. The scan tool will enter a cycle and cool down period for solenoid valves. The cool down period cannot be overridden.
- If Diagnostic Trouble Codes (DTCs) are set, scan tool will display DTCS PRESENT, or list DTCs depending on when DTCs were set. Select TROUBLE CODES to display or clear codes. If DTCs are set, proceed to DIAGNOSTIC TESTS . If bleed procedure was aborted but no DTCs are set, see INTERMITTENTS & POOR CONNECTIONS or SYMPTOM DIAGNOSIS under DIAGNOSIS & TESTING. Repair ABS/TCS as necessary before continuing.
- When auto bleed procedure is complete, depress brake pedal. Brake pedal should be high and firm. If brake pedal is not high and firm, reinspect brake system for leaks or damage. If brake system is okay and pedal travel is still excessive, repeat auto bleed procedure.
- Remove scan tool. Remove pressure bleeding equipment if used. Reinstall wheels and lower vehicle. Fill master cylinder reservoir with fluid as necessary. Road test vehicle. If brake pedal is spongy, perform conventional brake bleeding procedure. See MANUAL BLEEDING PROCEDURE or PRESSURE BLEEDING PROCEDURE .