Do you have any warning light on dashboard?
The Anti-Lock Brake System (ABS) allows the driver to stop in the shortest distance while maintaining steering control. During normal anti-lock operation a pulsation in brake pedal and a clicking sound will be sensed. System consists of a master cylinder/booster assembly, ABS control module, Hydraulic Control Unit (HCU), electric pump/motor, G-switch, acceleration sensor (4WD), 4 wheel sensors, and 2 warning lights.
The Rear Anti-Lock Brake System II (RABS II) is designed to prevent rear brake lock-up by controlling hydraulic fluid pressure to the rear wheel cylinders. The system consists of 2 warning lights (Red BRAKE and Yellow ABS), an RABS module, an electrohydraulic RABS valve, Brake Pedal Position (BPP) switch, brake fluid level switch, RABS speed sensor and exciter/sensor ring.
RABS module continuously monitors rear (axle mounted) wheel speed sensor input. It compares the rate of deceleration with programed normal stopping distance. If impending lock-up occurs, the module energizes the RABS valve.
RABS valve contains an isolation and a dump valve operated by solenoids controlled by the RABS module. The isolation valve prevents additional pressure from being fed to rear brake system and dump valve releases pressure from rear brake system.
RABS valve will store "dumped" brake fluid until brake pressure is released, and then releases it back to brake master cylinder reservoir.
RABS SELF-TEST CAPABILITY
RABS module performs a system test during start-up and normal operation. Red BRAKE warning light indicates low fluid level or parking brake applied. If a problem is detected, the module will be deactivated and a Yellow ABS warning light will be illuminated. Both warning lights should illuminate for about 2 seconds when ignition is turned on or when cranking engine.
When Yellow ABS warning light illuminates during normal operation, the system has detected a problem and stored a Diagnostic Trouble Code (DTC). Loss of power to module will cause system to be deactivated and Yellow ABS warning light to be illuminated, but will not set a DTC.
Sunday, December 7th, 2008 AT 8:22 PM