Immobilizer Cm

Detecting condition: 

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

Trouble symptom: 

Not communicable with Subaru Select Monitor.

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 CM.

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

   Connector & terminal 

   (i34) No. 2 (+) - Chassis ground (-):

   (i34) No. 1 (+) - Chassis ground (-):

   Is the voltage 10 - 13 V?

   Yes: Go to  4 .

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

4. CHECK HARNESS  .

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

   Connector & terminal 

   (i34) No. 16 - Chassis ground:

   Is the resistance less than 1 Ω?

   Yes: Go to  5 .

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

5. CHECK IMMOBILIZER CM  .
   1. Turn the ignition switch to OFF.
   2. Connect the immobilizer CM connector.
   3. Perform communication with the immobilizer CM.

   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 CM. Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE .