Anti-Lock Brake System: Description
Anti-Lock Brake System (ABS) consists of speed sensors (on both front rotors and in rear axle), an Electronic Control Unit (ECU) (under right side of instrument panel on 240, left side of instrument panel on 740 and 940), and a hydraulic modulator (in engine compartment). See Fig 1 .
The hydraulic modulator consists of front and rear pressure control solenoids and relays, a return motor pump and relay, and ECU connector. Modulator pressure control solenoids are mounted inside hydraulic modulator and are not individually serviceable. Replace modulator assembly if solenoids are defective.
An ABS warning light in the instrument panel will remain illuminated if an ABS failure occurs. If an ABS malfunction occurs, conventional braking system takes over. The vehicle may be safely driven when ABS warning light is on.