Testing Precautions
The ECU cannot store trouble codes with same first digit (25 and 26). Lowest number code (25) will be stored first. Codes must be serviced in order received, and cleared before continuing. Drive vehicle at approximately 25 MPH and check for additional codes. Solenoid valve service codes will override all other codes stored. If no codes are stored, system has passed self-test. If codes appear, refer to ON-BOARD SELF-TEST TROUBLE CODE INDEX . If BRAKE warning light is on or comes on intermittently, go to WARNING LIGHT SYMPTOM SEQUENCE CHART. See Figure .