2006 Subaru B9 Tribeca Owner's Manual - Page 231

Starting and operating 7-17 When you feel the ABS system operating, you should maintain constant brake pedal pressure. Do not pump the brake pedal since doing so may defeat the operation of the ABS system. The ABS system prevents the lock-up of wheels which may occur during sudden braking or braking on slippery road surfaces. This helps prevent the loss of steering control and directional stability caused by wheel lock-up. When the ABS system is operating, you may hear a chattering noise or feel a slight vibration in the brake pedal. This is normal when the ABS operates. The ABS system will not operate when the vehicle speed is below approximately 6 mph (10 km/h). ABS warning light 700314 The ABS warning light comes on when the ignition switch is turned to the "ON" position and goes out after approximately two seconds. This is an indication that the ABS system is working properly. The warning light does not come on when the ignition switch is turned to the "ON" position. The warning light comes on when the ignition switch is turned to the "ON" position, but it does not go out even when the vehicle speed exceeds approximately 8 mph (12 km/h). The warning light comes on during driving. If these occur, have the ABS system repaired at the first available opportunity by your SUBARU dealer. NOTE If the warning light behavior is as described in the following, the ABS system may be considered normal. The warning light comes on right after the engine is started but goes out immediately, remaining off. The warning light remains on after the engine has been started, but it goes out when the vehicle speed reaches approximately 8 mph (12 km/h). The warning light comes on during driving, but it goes out immediately and remains off. When driving with an insufficient battery - CONTINUED - ABS system self-check You may feel a slight shock in the brake pedal and hear the operating sound of ABS from the engine compartment just after the vehicle is started. This is caused by an automatic functional test of the ABS system being carried out and does not indicate any abnormal condition. If the warning light behaves as follows, the ABS system may not be working properly. When the warning light is on, the ABS function shuts down; however, the conventional brake system continues to operate normally.