Electronic Brake Control Module (EBCM)
The Electronic Brake Control Module (EBCM) is a small control computer, mounted under the dash to the left of the steering column, which monitors the speed of each wheel as well as several functions internal to the hydraulic unit. The primary functions of the EBCM are to detect wheel locking and wheel slip tendencies, control the brake system while in anti-lock mode or traction control mode, and monitor the system for proper operation. The EBCM also controls display of ABS/TCS diagnostic trouble codes while in diagnostic mode. See Fig 1 .
The EBCM continuously checks the speed of each wheel to determine if any wheel is beginning to lock or slip. If a wheel locking tendency is detected, the EBCM commands appropriate valve positions to modulate brake fluid pressure in some or all of the hydraulic circuits to prevent wheel lock-up and provide optimum braking. The EBCM continues to control pressure in individual hydraulic circuits until a locking tendency is no longer present.
If the EBCM detects that a wheel is beginning to slip or lose traction in one of the front wheels, it will apply the brake to that wheel to bring it to any acceptable slip rate. The EBCM will command the appropriate solenoid valve position in the plunger unit and modulate brake fluid pressure in one or both front hydraulic circuits until the tendency for the wheel to slip is no longer detected.
The Anti-Lock Brake and Traction Control System are constantly monitored by the EBCM for proper operation. If the EBCM detects an error, it can disable the anti-lock function and/or turn on the Red BRAKE warning lamp in the instrument panel cluster (IPC). The EBCM will also disable the traction system and/or inform the driver by turning on the Red BRAKE warning lamp or displaying a message on the CCDIC.