Faulty Solenoid Valve Relay Or System Interruption

1. Ensure ignition is off. Disconnect ABS control unit harness connector. See Figure . Turn ignition on. Using voltmeter, measure voltage between control unit harness connector terminals No. 1 and 20. See Figure . If battery voltage is not present, inspect and repair circuit(s) as needed. See WIRING DIAGRAM at the end of this article. If battery voltage is present, go to next step.
2. Turn ignition is off. Remove ABS harness connector cover. Connect control unit harness connector. Turn ignition on. Using voltmeter, backprobe harness connector. Measure voltage between terminals No. 17 and 20. See Figure . If voltage is less than battery voltage, replace ABS control unit. If battery voltage is present, go to next step.
3. With ABS harness connector still connected, backprobe connector terminals No. 20 and 32. If voltage is less than battery voltage, go to next step. If battery voltage is present, replace ABS control unit.
4. Turn ignition off. Disconnect ABS harness connector and hydraulic unit harness connector. Using ohmmeter, check resistance of specified circuits. See HARNESS CONTINUITY CHECK table. Resistance should 0 ohms. If continuity does not exist, inspect and repair circuit as needed. See WIRING DIAGRAM at the end of this article.
   HARNESS CONTINUITY CHECK
   
   

   ABS Terminal	Hydraulic Unit Terminal
   17	6
   32	11
   27	12

5. Turn ignition off. Disconnect hydraulic unit motor harness connector. Using voltmeter, measure voltage between harness connector terminal No. 1 (White/Green wire) and ground. If battery voltage is not present, inspect and repair circuit as needed. See WIRING DIAGRAM at the end of this article. If battery voltage is present, go to next step.
6. Remove hydraulic unit valve relay. Hydraulic unit valve relay (5 terminal) is located on hydraulic unit. Check continuity of relay. See Figure . Check resistance between relay terminals 85 and 86. Resistance should be 93-113 ohms. Replace relay if measurements and/or continuity is not as specified. If relay is okay, replace hydraulic unit. See REMOVAL & INSTALLATION.

Fig 1: Checking Hydraulic Unit Solenoid Relay

Courtesy of SUBARU OF AMERICA, INC.