Diagnostic Procedure for Subaru Select Monitor Communication: Inspection

Trouble symptom: 

Cannot communicate with [P-HEV Drive Motor].

Detecting condition: 

• Defective Wire harness connector
• Power supply circuit malfunction
• Inverter with converter assembly malfunctioning
• Defective CAN communication circuit
• Defective Subaru Select Monitor

Wiring diagram: 

Hybrid system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>HYBRID ELECTRIC VEHICLE SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK FUSE  .
   1. Turn the ignition switch to OFF.
   2. Check the fuse. Ref. to HYBRID ELECTRIC VEHICLE>RELAY AND FUSE .

   Is there any fault?

   Yes:  Replace the fuse. If the replaced fuse blows out easily, repair the short circuit to ground in the Wire harness between the fuse and the - Inverter with converter assembly.

   No:  Go to  2.

2. CHECK POWER SUPPLY CIRCUIT (OPEN)  .
   1. Disconnect the Inverter with converter assembly connector.
   2. Turn the ignition switch to ON.
   3. Using a tester, measure the voltage between Inverter with converter assembly connector and chassis ground.

   Connector & terminal 

   (HV23) No. 1 (+) - Chassis ground (-):

   (HV23) No. 5 (+) - Chassis ground (-):

   Is the voltage 10 V or more?

   Yes:  Go to  3.

   No:  Repair the open circuit in Wire harness between the fuse and the Inverter with converter assembly.

3. CHECK GROUND CIRCUIT (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Using a tester, measure the resistance between Inverter with converter assembly connector and chassis ground.

   Connector & terminal 

   (HV23) No. 4 - Chassis ground:

   (HV23) No. 8 - Chassis ground:

   Is the resistance less than 1 Ω?

   Yes:  Go to  4.

   No:  Repair the open circuit in Wire harness between Inverter with converter assembly - chassis ground.

4. CHECK LAN SYSTEM  .
   1. Connect the Inverter with converter assembly connector.
   2. Inspect LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS) (HEV)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

   Is there any fault?

   Yes:  Perform the inspection according to the diagnosis for LAN system.

   No:  Go to  5.

5. CHECK Inverter with converter assembly  .

   Communicate with [P-HEV Drive Motor].

   Is communication possible?

   Yes:  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, or temporary open or short circuit of the Wire harness may be the cause.

   No:  Replace Inverter with converter assembly. Ref. to HYBRID ELECTRIC VEHICLE>INVERTER AND CONVERTER ASSEMBLY .