System Self-Test

When the ignition switch is turned-on the microprocessor is tested. If an error occurs during the test, a DTC will be set into the memory. However it is possible the DTC will not be stored in memory if the error has occurred in the module were the DTCS are stored. 

The ABM contains a self check program that illuminates the ABS warning light when a system fault is detected. Faults are stored in memory and are accessible with the scan tool. 

ABS faults remain in memory until cleared, or until after the vehicle is started approximately 50 times. 

Stored faults are not erased if the battery is disconnected.