DTC B1413: Immobilizer Control Module Battery Power Supply

Diagnosis start condition:

Battery voltage is 10 V or more.
The remote engine starter was not used to start the engine.

DTC detecting condition:

Battery voltage for the immobilizer Control Module was outside the specification for a certain period of time.

Trouble symptom:

The security indicator does not blink after the ignition key is turned to OFF.

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: When the immobilizer Control Module is replaced, registration of the immobilizer system is required. For details, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.

CHECK FUSE .
1. Turn the ignition switch to OFF.
2. Check the fuse. Ref. to WIRING SYSTEM>IMMOBILIZER SYSTEM>WIRING DIAGRAM .
Is the check result OK?

Yes: Go to 2.

No: Replace the fuse. If the fuse blows out easily, repair the short circuit to power supply in harness between the battery and immobilizer Control Module.
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: Go to 3.

No: Go to 5.
CHECK DATA MONITOR .
1. Turn the ignition switch to OFF.
2. Disconnect the ground terminal from battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
3. Wait for at least 10 seconds.
4. Connect the ground terminal to battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
5. Turn the ignition switch to ON.
6. Using the Subaru Select Monitor, check the following items in the [Data monitor] of [Immobilizer]. Ref. to IMMOBILIZER (DIAGNOSTICS)>DATA MONITOR .
  - Battery Voltage
Is the display 10 V or more?

Yes: Go to 4.

No: Go to 5.
CHECK DTC .
Read the DTC of [Immobilizer] using the Subaru Select Monitor. Ref. to IMMOBILIZER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC B1413 displayed? (Current code)

Yes: Replace the immobilizer Control Module. Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE .

No: Even if DTC is displayed, 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.
CHECK IMMOBILIZER CONTROL MODULE POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from immobilizer Control Module.
3. Measure the voltage between immobilizer Control Module connector and chassis ground.
  Connector & terminal
  
  (i94) No. 1 (+) - Chassis ground (-):
Is the voltage 10 V or more?

Yes: Go to 6.

No: Repair the open circuit of harness between the immobilizer Control Module and fuse.
CHECK IMMOBILIZER CONTROL MODULE GROUND CIRCUIT .
Measure the resistance between immobilizer Control Module connector and chassis ground.

Connector & terminal

(i94) No. 5 - Chassis ground:

Is the resistance less than 10 Ω?

Yes: Replace the immobilizer Control Module. Ref. to SECURITY AND LOCKS>IMMOBILIZER CONTROL MODULE .

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