Antilock Telltale Lamp
As a bulb and system check, the lamp will come On with the key On and the lamp will turn Off after about 3 seconds. If the lamp remains On, the self-diagnostic system has detected a problem. The lamp will remain on until the ignition is cycled Off. When the ignition is cycled back On the ABS, runs the self diagnostic test to see if the problem is still present. If the problem remains the light will stay On.
If the lamp comes On solid, it informs the driver that a problem has occurred and that the ABS system has been disabled. The vehicle should be taken for service as soon as possible.