See Figure 1
The 4WABS module performs system tests and self-tests during startup and normal operation. The valve, sensor and fluid level circuits are monitored for proper operation. If a fault is found, the 4WABS will be deactivated and the amber ANTI LOCK light will be lit until the ignition is turned OFF. When the light is lit, the Diagnostic Trouble Code (DTC) may be obtained. Under normal operation, the light will stay on for about 2 seconds while the ignition switch is in the ON position and will go out shortly after.
The Diagnostic Trouble Codes (DTC) are an alphanumeric code and a scan tool, such as the Special Service Tool NGS (New Generation Star) Tester 49-T088-0A0, is required to retrieve the codes. The DTC code chart has been included.