Automatic Tests

Turn ignition on. Using Tech 1, select F4: ABS TESTS and then F1: AUTO TEST. Press ENTER when ready. Valves can be heard and felt cycling from hydraulic control unit. Have assistant verify pump motor is turned on. See DIAGNOSTIC TROUBLE CODE (DTC) table if DTCs are set. Perform appropriate DIAGNOSTIC TROUBLE CODE (DTC) CHART. After all diagnosis and repairs are completed, clear DTCs and verify operation. AUTO test is performed automatically by EBCM once during each ignition cycle when vehicle reaches approximately 4 MPH.