Diagnostic Procedure For Subaru Select Monitor Communication: Inspection: Immobilizer

Detecting condition: 

• Defective harness
• Power supply circuit malfunction
• Defective immobilizer control module
• Body integrated unit malfunctioning
• Defective CAN communication circuit
• Defective Subaru Select Monitor

Trouble symptom: 

Communication with [Immobilizer] is faulty.

Wiring diagram: 

Immobilizer system Ref. to WIRING SYSTEM>IMMOBILIZER SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK FUSE  .

   Check the fuse.

   Is the check result OK?

   Yes  : Go to  2 .

   No  : Replace the fuse. If the replaced fuse blows out easily, repair the ground short circuit in the harness between the battery and immobilizer control module.

2. CHECK LAN SYSTEM  .

   Inspect LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is the check result OK?

   Yes  : Go to  3 .

   No  : Perform the inspection according to the diagnosis for LAN system.

3. CHECK DATA MONITOR  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor, check the following items in the [Data monitor] of [Immobilizer]. Ref. to Immobilizer (Diagnostics)>Data Monitor .
      • BATT voltage

      Is the display 10 V or more?

      Yes  : Replace the immobilizer control module. Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE .

      No  : Go to  4 .

4. CHECK HARNESS  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the immobilizer control module connector.
   3. Turn the ignition switch to ON.
   4. Using a tester, measure the voltage between the immobilizer control module connector and chassis ground.

      Connector and terminal 

      (i94) No. 2 (+) - Chassis ground (-):

      (i94) No. 1 (+) - Chassis ground (-):

      Is the voltage 10 - 13 V?

      Yes  : Go to  5 .

      No  : Repair the open circuit of harness between the immobilizer control module connector and fuse.

5. CHECK HARNESS  .

   Using a tester, measure the resistance between the immobilizer control module connector and chassis ground.

   Connector and terminal 

   (i94) No. 5 - Chassis ground:

   Is the resistance less than 1 Ω?

   Yes  : Go to  6 .

   No  : Repair the open circuit of harness between the immobilizer control module connector and chassis ground.

6. CHECK IMMOBILIZER CONTROL MODULE  .
   1. Turn the ignition switch to OFF.
   2. Connect the immobilizer control module connector.
   3. Perform communication with the immobilizer control module.

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

      No  : Replace the immobilizer control module. Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE .