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The CAB monitors wheel speed sensor inputs continuously while the vehicle is in motion. However, the CAB will not During normal braking, the master cylinder, power booster and wheel brake units all function as they would in a The purpose of the antilock system is to prevent wheel lockup. Preventing lockup helps maintain vehicle braking The antilock CAB activates the system whenever sensor signals indicate periods of wheel slip. The antilock system prevents lockup during a wheel slip condition by modulating fluid apply pressure to the wheel Brake fluid apply pressure is modulated according to wheel speed, degree of slip and rate of deceleration. Sensors The ABS system has three fluid pressure control channels. The front brakes are controlled separately and the rear There are Two solenoid valves (Isolation and Dump valve) which are used in each antilock control channel. The During an ABS stop the ISO valve is energized which acts to prevent further pressure build-up to the calipers. Then STANDARD PROCEDURE ABS BRAKE BLEEDING ABS system bleeding requires conventional bleeding methods plus use of the DRB scan tool. The procedure 1. Perform base brake bleeding, (Refer to 5 - BRAKES - STANDARD PROCEDURE) OR (Refer to 5 - BRAKES - STANDARD PROCEDURE). 2. Connect scan tool to the Data Link Connector. 3. Select ANTILOCK BRAKES, followed by MISCELLANEOUS, then ABS BRAKES. Follow the instructions dis- played. When scan tool displays TEST COMPLETE, disconnect scan tool and proceed. 4. Perform base brake bleeding a second time, (Refer to 5 - BRAKES - STANDARD PROCEDURE) OR (Refer to 5 - BRAKES - STANDARD PROCEDURE). 5. Top off master cylinder fluid level and verify proper brake operation before moving vehicle. 5 - 288 BRAKES - ABS - SERVICE INFORMATION DR/DH |