1999 Subaru Forester Owner's Manual - Page 217

This is an indication that the ABS system is working properly. If the warning light behaves as follows, ABS system may not work properly. D The warning light does not come on when the ignition switch is turned to the "ON" position. D 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 8mph (12km/h). D The warning light comes on during driving. When the warning light is on, the ABS function shuts down; however, the conventional brake system continues to operate normally. If this occurs, have the ABS system repaired at the first available opportunity by your SUBARU dealer. NOTE If the warning light behavior is as shown below, the ABS system may be considered normal. D The warning light comes on right after the engine is started but goes out immediately, remaining off. D The warning light remains on after the engine has been started, but it goes out when the vehicle speed reaches about 8 mph (12 km/h). D The warning light comes on during driving, but it goes out immediately and remains off. When driving with an insufficient battery voltage such as when the engine is jump started, the ABS warning light may come on. This is due to the low battery voltage and does not indicate a malfunction. When the battery becomes fully charged, the light will go out. 7-32