Abs Control

Using primarily the wheel speed data from each ABS sensor and secondarily the vehicle deceleration rate data from the G sensor as parameters, the ABSCM generates a simulated vehicle speed when there is a risk of wheel lock-up. Using the simulated vehicle speed (called "dummy" vehicle speed) as a reference, the ABSCM determines the state of the wheel in terms of the tendency toward lock-up. If the result shows that the wheels are about to lock, the ABSCM issues commands to energize or de-energize the solenoid valves and activate the motor pump of the H/U to modulate the brake fluid pressures that act on the wheel cylinders, thereby preventing the wheels from locking.

The ABSCM controls the right and left front wheel fluid pressures independently and the rear wheel fluid pressures based on the wheel which is the most likely to lock (select-low control).

• Functions available using SUBARU select monitor.

  When the SUBARU select monitor is connected, the ABSCM allows it:

  • To read out analog data
  • To read out ON/OFF data
  • To read out or erase trouble code
  • To read out status information in the event of a fault (freeze frame data)
  • To initiate ABS sequence control pattern
• Indication functions

  Under the control of the ABSCM, the ABS warning light provides the following three indication functions:

  • ABS fault alerting
  • Trouble code indication (by flashing in the diagnosis mode)
  • Valve ON/OFF indication (when sequence control pattern is initiated)