Starter Motor Circuit: Wiring Diagram

WARNING: This page is about a different variant/trim than selected.

Fig 1: Starter Motor Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK BATTERY. Check the battery voltage.	Is the voltage 12 V or more?	Go to step 2 .	Charge or replace the battery.
2 CHECK OPERATION OF STARTER MOTOR.	Does the starter motor operate?	Go to step 3 .	Go to step 4 .
3 CHECK DTC.	Is DTC displayed? Refer to , OPERATION , Read Diagnostic Trouble Code (DTC).	Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to , LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
4 CHECK INPUT SIGNAL FOR STARTER MOTOR. Turn the ignition switch to OFF. Disconnect the connector from starter motor. Place the select lever in "P" range or "N" range. Turn the ignition switch to START. Measure the voltage between the starter motor connector and the engine ground. Connector & terminal (B14) No. 1 (+) - Engine ground (-):	Is the voltage 10 V or more?	Check the starter motor. Refer to STARTER Starter.	Go to step 5 .
5 CHECK INPUT SIGNAL FOR STARTER MOTOR. Place the select lever in "P" range or "N" range. Turn the ignition switch to START. Measure the voltage between starter relay connector and chassis ground. Connector & terminal (B493) No. 3 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Repair the open circuit of the harness between starter relay connector and starter motor.	Go to step 6 .
6 CHECK HARNESS BETWEEN BATTERY AND IGNITION SWITCH CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from ignition switch. Measure the voltage between ignition switch connector and chassis ground. Connector & terminal (B72) No. 3 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 7 .	Repair the power supply circuit.
7 CHECK IGNITION SWITCH. Measure the resistance between ignition switch terminals after turning the ignition switch to START position. Terminals No. 3 - No. 2: No. 3 - No. 6:	Is the resistance less than 1 Ω?	Go to step 8 .	Replace the ignition switch. Refer to IGNITION KEY LOCK REPLACEMENT, Ignition Key Lock.
8 CHECK INPUT VOLTAGE OF STARTER RELAY. Remove the starter relay. Connect the connector to ignition switch. Turn the ignition switch to START. Measure the voltage between starter relay connector and chassis ground. Connector & terminal (B493) No. 4 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 9 .	Repair the open circuit of harness between starter relay connector and ignition switch connector.
9 CHECK STARTER RELAY. Connect the battery to starter relay terminals No. 1 and No. 2. Measure the resistance between starter relay terminals. Terminals No. 3 - No. 4:	Is the resistance less than 1 Ω?	Go to step 10 .	Replace the starter relay.
10 CHECK HARNESS BETWEEN ECM AND STARTER RELAY CONNECTOR. Turn the ignition switch to OFF. Disconnect the connectors from ECM. Measure the resistance of harness between ECM and starter relay connector. Connector & terminal (B135) No. 26 - (B493) No. 1: (B136) No. 16 - (B493) No. 3:	Is the resistance less than 1 Ω?	Go to step 11 .	Repair the open circuit of harness between ECM and starter relay connector.
11 CHECK INPUT VOLTAGE OF STARTER RELAY. Connect the connector to ECM. Place the select lever in "P" range or "N" range. Turn the ignition switch to START. Measure the voltage between starter relay connector and chassis ground. Connector & terminal (B493) No. 2 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 12 .	Go to step 13 .
12 CHECK HARNESS BETWEEN ECM AND INHIBITOR RELAY CONNECTOR. Turn the ignition switch to OFF. Disconnect the inhibitor relay connector. Measure the resistance of harness between ECM and inhibitor relay connector. Connector & terminal (B136) No. 35 - (B498) No. 1:	Is the resistance less than 1 Ω?	Check the ECM power supply and ground line. Refer to , CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM) , Diagnostics for Engine Starting Failure.	Repair the open circuit of harness between ECM and inhibitor relay connector.
13 CHECK INPUT VOLTAGE OF INHIBITOR RELAY. Turn the ignition switch to OFF. Disconnect the inhibitor relay connector. Turn the ignition switch to START. Measure the voltage between inhibitor relay connector and chassis ground. Connector & terminal (B498) No. 2 (+) - Chassis ground (-): (B498) No. 4 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 14 .	Check the following item and repair if necessary. Blown-out of fuse (F/B No. 21) Open or ground short circuit of harness between ignition switch connector and inhibitor relay connector
14 CHECK INHIBITOR RELAY. Connect the battery to inhibitor relay terminals No. 1 and No. 2. Measure the resistance between inhibitor relay terminals. Terminals No. 3 - No. 4:	Is the resistance less than 1 Ω?	Go to step 15 .	Replace the inhibitor relay.
15 CHECK HARNESS BETWEEN INHIBITOR RELAY CONNECTOR AND STARTER RELAY CONNECTOR. Turn the ignition switch to OFF. Measure the resistance of harness between inhibitor relay connector and starter relay connector. Connector & terminal (B498) No. 3 - (B493) No. 2:	Is the resistance less than 1 Ω?	Repair the open circuit of harness between TCM and inhibitor relay connector.	Repair the open circuit of harness between inhibitor relay connector and starter relay connector.