Forester, Impreza 2.5L & Outback Sport
- Turn ignition off. Remove main relay. Main relay is located under left side of dash on Forester (right side of dash on Impreza 2.5L and Outback Sport). Using jumper wires, connect battery voltage to relay terminal No. 1 and ground terminal No. 2. Using a DVOM, measure resistance between terminals No. 3 and 5 and between terminals No. 4 and 6. See Fig 1 . If resistance is less than 10 ohms at both test points, go to next step. If resistance is not less than 10 ohms at both test points, replace main relay.
- Turn ignition off. Disconnect connectors from Engine Control Module (ECM) located under right side of instrument panel behind glove compartment. Using a DVOM, measure resistance between specified terminals on harness side of specified ECM electrical harness connector and good chassis ground point. See ECM GROUND CIRCUIT RESISTANCE (FORESTER, IMPREZA 2.5L & OUTBACK SPORT)
table. See Fig 2
. If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit in suspect ground circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.ECM GROUND CIRCUIT RESISTANCE (FORESTER, IMPREZA 2.5L & OUTBACK SPORT)
ECM Connector & Terminal No. (Wire Color) Specification 35-Pin B134 7 (Black/Green) Less Than 5 Ohms 8 (Black/White) Less Than 5 Ohms 27 (Black) Less Than 5 Ohms 34 (Black/Yellow) Less Than 5 Ohms 35 (Black/Yellow) Less Than 5 Ohms 28-Pin B135 - Manual Transaxle Only 25 (Black/Red) Less Than 5 Ohms 30-Pin B136 21 (Black/Red) Less Than 5 Ohms 22 (Black/Red) Less Than 5 Ohms - With ignition off and all ECM connectors still disconnected, measure voltage between harness side of 30-pin ECM electrical harness connector B136 terminal No. 9 (Black/Red wire) and good chassis ground point. See Fig 2 . If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- With ignition off, ensure all ECM connectors are still disconnected. Turn ignition on and measure voltage between harness side of 28-pin ECM electrical harness connector B135 terminal No. 7 (Green/Red wire) and good chassis ground point. See Fig 2 . If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair ignition power feed circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Turn ignition off and leave all ECM connectors disconnected. Using a DVOM, measure resistance between harness side of 28-pin ECM electrical harness connector B135 terminal No. 19 (Light Green/White wire) and good chassis ground point. See Fig 2 . If resistance is greater than one megohm, go to next step. If resistance is not greater than one megohm, repair short to ground in Light Green/White wire between ECM and main relay, and check ECM for damage. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Turn ignition off and reconnect all ECM connectors. Turn ignition on. Backprobing, measure voltage between harness side of 28-pin ECM electrical harness connector B135 terminal No. 19 (Light Green/White wire) and good chassis ground point. See Fig 2 . If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, replace ECM.
- Turn ignition off. Disconnect main relay Brown 6-pin electrical harness connector. Turn ignition on. Using a DVOM, measure voltage between main relay Brown 6-pin electrical harness connector terminal No. 2 (Light Green/White wire) and good chassis ground point. See Fig 3 . If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open circuit in Light Green/White wire between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Ensure ignition is off and main relay Brown 6-pin electrical harness connector is disconnected. Using a DVOM, measure resistance between main relay Brown 6-pin electrical harness connector terminal No. 1 (Black wire) and good chassis ground point. See Fig 3 . If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair open circuit in ground circuit (Black wire) between main relay and chassis ground point located behind left headlight on Forester or behind right side of instrument panel on Impreza 2.5L and Outback Sport. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Ensure ignition is off and main relay Brown 6-pin electrical harness connector is disconnected. Using a DVOM, measure voltage of Black/Red wires between main relay Brown 6-pin electrical harness connector terminals No. 5 and 6 and good chassis ground point. See Fig 3 . If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair open or short to ground in power feed circuits (Black/Red wires) between main relay and main fuse block located in engine compartment. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
- Turn ignition off and reconnect main relay Brown 6-pin electrical harness connector. Turn ignition on. Backprobing, measure voltage on Yellow/Green wires (Yellow/Blue wires on Impreza 2.5L and Outback Sport) between 30-pin ECM electrical harness connector B136 terminals No. 1 and 2 and good chassis ground point. See Fig 2 . If voltage is greater than 10 volts, check ignition control system. See IGNITION CONTROL SYSTEM under IGNITION SYSTEMS. If voltage is not greater than 10 volts, repair open or short to ground in suspect wire(s) between ECM and main relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.