Diagnostic Procedure for Subaru Select Monitor Communication: Inspection: Notes

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Diagnosis:

Subaru Select Monitor communication line is open or shorted.

Trouble symptom:

Not communicable with Subaru Select Monitor.

Wiring diagram:

CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CHECK SUBARU SELECT MONITOR .
1. Connect the Subaru Select Monitor to another vehicle.
2. Check communication condition between Subaru Select Monitor and vehicle.
Is communication performed normally?

Yes : Go to 2.

No : Subaru Select Monitor unit or diagnosis cable is faulty. Or check the fuse on the vehicle side.
CHECK DATA LINK CONNECTOR .
Use a tester to check for continuity in the ground circuit.

Connector & terminal

(i221) No. 4 - Chassis ground:

(i221) No. 5 - Chassis ground:

Is there continuity?

Yes : Go to 3.

No : Repair or replace the open circuit.
CHECK DATA LINK CONNECTOR .
1. Turn the ignition switch to ON.
2. Using a tester, check the power supply of data link connector.
  Connector & terminal
  
  (i221) No. 8 (+) - Chassis ground (-):
  
  (i221) No. 16 (+) - Chassis ground (-):
Is the voltage 10 V or more?

Yes : Go to 4.

No : Check the power supply circuits to the data link connector.
CHECK COMMUNICATION FOR INITIALIZING ERROR .
Perform the communication for initializing with each module by connecting the Subaru Select Monitor. (For systems whose module can communicate with diagnostic devices)

NOTE:
By performing [CAN bus connected ECU], confirmation of minimal connection modules is possible. Ref. to LAN SYSTEM (DIAGNOSTICS)>CAN BUS CHECK

Is the communication possible with all modules?

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

No : Perform the inspection using the check sheet of communication for initializing. Ref. to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTIC PROCEDURE FOR SUBARU SELECT MONITOR COMMUNICATION>INSPECTION>CHECK USING THE CHECK SHEET OF COMMUNICATION FOR INITIALIZING