Trouble Code No. 9: Faulty Hydraulic Motor Or Motor Relay

Turn ignition off. Unplug ABS ECU connector. See ACCESSING ABS ECU CONNECTOR. Measure resistance between ABS ECU connector terminals No. 17 (Green/White wire) and No. 28 (Blue/White wire on Legacy; Blue/Yellow wire on SVX). If reading is 72-88 ohms for Legacy and 45-55 ohms for SVX, go to step 6).
If resistance is not as specified, unplug hydraulic control unit connectors. Measure resistance between hydraulic control unit terminals No. 5 (Green/White wire on Legacy; Blue/Yellow wire on SVX) and No. 6 (Blue/White wire on Legacy; Green/White wire on SVX). If reading is 45-55 ohms, go to step 4). If reading is not 45-55 ohms, remove ABS cover on hydraulic control unit and remove motor relay (4-terminal relay).
Connect ohmmeter to relay terminals No. 87 and 30. See Fig 1 . Apply 12 volts to relay terminals No. 85 and 86 (ground). Ohmmeter should indicate zero ohms. Remove 12 volts from relay; ohmmeter reading should be infinity. If either reading is not as specified, replace relay or repair connectors and wiring between ABS ECU and hydraulic control unit. If relay readings are as specified, replace hydraulic control unit.

Fig 1: Checking Hydraulic Motor Relay
Courtesy of SUBARU OF AMERICA, INC.

If reading between hydraulic control unit terminals No. 5 (Green/White wire on Legacy; Blue/Yellow wire on SVX) and No. 6 (Blue/White wire on Legacy; Green/White wire on SVX) is 45-55 ohms, ensure ABS ECU connector and hydraulic control unit connectors are unplugged. Use ohmmeter to measure resistance between each unit's connector terminals and from unit connector terminal to ground. See HYDRAULIC CONTROL UNIT HARNESS RESISTANCE I table.

HYDRAULIC CONTROL UNIT HARNESS RESISTANCE I

Connector Terminal No. ⁽¹⁾

Connector Terminal No. ⁽²⁾

Resistance (Ohms)

Legacy

HCU/(F9) 6

ECU/(P12) 28

HCU/(F9) 5

ECU/(P12) 17

HCU/(F9) 6

Ground

Infinity

HCU/(F9) 4

Ground

Infinity

SVX

HCU/(R1) 5

ECU/(R7) 28

HCU/(R1) 6

ECU/(R7) 17

HCU/(R1) 5

Ground

Infinity

HCU/(R1) 6

Ground

Infinity

⁽¹⁾	Hydraulic Control Unit (HCU) connector.

⁽²⁾	ABS Electronic Control Unit (ECU) connector.

If any resistance is not as specified, repair appropriate wiring as required and retest system. If all resistances are as specified, replace hydraulic control unit and retest system.
If reading was 45-55 ohms in step 1), unplug both connectors from hydraulic control unit. Using an ohmmeter, measure resistance between hydraulic control unit 2-pin (control unit side - F8 on Legacy; F43 on SVX) connector terminal No. 2 (White/Red wire) and hydraulic control unit 12-pin (control unit side - F9 on Legacy; R1 on SVX) connector terminal No. 4 (Blue/White wire on Legacy; Blue/Black wire on SVX).
If reading is less than infinity, remove motor relay. Go to step 9). If reading is infinity, motor relay is good. Check and repair voltage input wiring to hydraulic control unit. To check voltage input wiring to hydraulic control unit, turn ignition on.
Measure voltage between hydraulic control unit 2-pin (F8 on Legacy; F43 on SVX) connector terminal No. 2 (White/Red wire) and ground. Reading should be 10-12 volts. Repair wiring as required. See Figure or Figure .
Remove ABS cover on hydraulic control unit, and remove motor relay (4-terminal relay). Connect ohmmeter to relay terminals No. 87 and 30. See Fig 1 . Apply 12 volts to relay terminals No. 85 and 86 (ground). Ohmmeter should indicate zero ohms.
Remove 12 volts from relay. Ohmmeter reading should be infinity. If either reading is not as specified, replace relay. If relay readings are as specified, replace hydraulic control unit.