Diagnostic System Description

1. Diagnose ABS system with self-diagnosis checker and ABS warning light on instrument panel. DO NOT turn ignition switch to ON position while ABS-related connector(s) are disconnected. This will cause a Diagnostic Trouble (DTC) to be stored in ABS control unit memory. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTC).
2. After repairs are made, erase all DTCs. See ERASING DTC. The ABS warning light illuminates under the following conditions:
   • Vehicle operated on snow or ice with parking brake activated, or a dragging brake at one wheel.
   • Tire size is changed from original size.
   • Tires with different traction characteristics are used on same axle.
   • Vehicle is jacked up and drive wheels spin for 20 seconds or more with ignition on.
   • Low battery voltage.

If ABS warning light illuminates because of these conditions, turn ignition off and then back on. ABS warning light will go out and no DTCs for described conditions will be stored in ABS control unit memory.