Starter Motor Circuit: Wiring Diagram

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 Refer to "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. 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 (-): NOTE: For CVT model, place the select lever in "P" range or "N" range. For MT model, depress the clutch pedal.	Is the voltage 10 V or more?	Check the starter motor. Refer to STARTER Starter.	Go to step 5.
5 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 6.	Repair the power supply circuit.
6 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 7.	Replace the ignition switch. Refer to IGNITION KEY LOCK , REPLACEMENT, Ignition Key Lock.
7 CHECK INPUT VOLTAGE OF STARTER RELAY. Turn the ignition switch to OFF. Remove the starter relay. Connect the connector to ignition switch. Measure the input voltage between starter relay connector and chassis ground after turning the ignition switch to START position. Connector & terminal (B493) No. 2 (+) - Chassis ground (-): (B493) No. 4 (+) - Chassis ground (-):	Is the voltage 10 V or more?	Go to step 8.	Repair open or short circuit to ground in harness between starter relay and ignition switch connector.
8 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 9.	Replace the starter relay. Refer to , ELECTRICAL COMPONENT LOCATION .
9 CHECK TRANSMISSION TYPE.	Is the transmission type CVT?	Go to step 10.	Go to step 14.
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 connector between ECM and starter relay. Connector & terminal (B493) No. 1 - (B135) No. 26:	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 HARNESS BETWEEN STARTER RELAY AND INHIBITOR SWITCH CONNECTOR. Disconnect the connector from inhibitor switch. Measure the resistance of harness between starter relay connector and inhibitor relay connector. Connector & terminal (B493) No. 3 - (T7) No. 6:	Is the resistance less than 1 Ω?	Go to step 12.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between starter relay connector and inhibitor switch connector Poor contact of coupling connector
12 CHECK HARNESS BETWEEN INHIBITOR SWITCH AND STARTER MOTOR. Measure the resistance of harness between the inhibitor switch and starter motor. Connector & terminal (T7) No. 9 - (B14) No. 1:	Is the resistance less than 1 Ω?	Go to step 13.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between inhibitor switch connector and starter motor Poor contact of coupling connector
13 CHECK INHIBITOR SWITCH. Place the select lever in "P" range or "N" range. Measure the resistance between inhibitor switch terminals. Terminals No. 6 - No. 9:	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.	Replace the inhibitor switch. Refer to INHIBITOR SWITCH Inhibitor Switch.
14 CHECK HARNESS BETWEEN STARTER RELAY AND CLUTCH STROKE SENSOR CONNECTOR. Turn the ignition switch to OFF. Disconnect the connector from clutch stroke sensor. Measure the resistance of harness between starter relay connector and clutch stroke sensor connector. Connector & terminal (B493) No. 1 - (B501) No. 2:	Is the voltage 10 V or more?	Go to step 15.	Repair the open circuit in harness between starter relay connector and clutch stroke sensor connector.
15 CHECK HARNESS BETWEEN ECM AND CLUTCH STROKE SENSOR CONNECTOR. Disconnect the connectors from ECM. Measure the resistance of harness between ECM and clutch stroke sensor connector. Connector & terminal (B135) No. 26 - (B501) No. 1:	Is the resistance less than 1 Ω?	Go to step 16.	Repair the open circuit of harness between ECM and clutch stroke sensor connector.
16 CHECK CLUTCH STROKE SENSOR. Measure the resistance between clutch stroke sensor terminals while depressing the clutch. Terminals No. 1 - No. 2:	Is the resistance less than 1 Ω?	Go to step 17.	Replace the clutch stroke sensor. Refer to ELECTRICAL COMPONENT LOCATION Electrical Component Location.
17 CHECK HARNESS BETWEEN STARTER RELAY AND STARTER MOTOR. Measure the resistance of harness between starter relay connector and starter motor. Connector & terminal (B493) No. 3 - (B14) 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 the harness between starter relay connector and starter motor.