ATTENTION:
GENERAL MANAGER

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PARTS MANAGER

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CLAIMS PERSONNEL

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IMPORTANT - All
Service Personnel
Should Read and
Initial in the boxes
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SERVICE MANAGER

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© 2025 Subaru of America, Inc. All rights reserved.

SERVICE INFORMATION BULLETIN
APPLICABILITY:

2025MY Forester
2024MY Impreza & Crosstrek

NUMBER: 18-226-25R
DATE:

02/12/25

SUBJECT:

DTC B2A16 (Immobilizer Key Collation
Diagnosis) Service Manual Correction

REVISED:

06/09/25

INTRODUCTION:
This Service Information Bulletin provides the Service Manual Correction to the diagnostic
procedure for DTC B2A16 (Immobilizer Key Collation Diagnosis). The immobilizer re-registration
process must be completed during the diagnosis and repair procedure. Refer to the procedures
outlined in this bulletin when diagnosing DTC B2A16. This correction will be added to the Service
Manual at a later date.
SERVICE PROCEDURE / INFORMATION:
Listed below, is a section of the current Service Manual with the correction outlined in RED. This
information is to be used in conjunction with the current Service Manual.
Refer to STIS: DIAGNSTICS > TELEMATICS SYSTEM (DIAGNOSTICS) > Diagnostic Procedure
with Diagnostic Trouble Code (DTC) > DTC B2A16 IMMOBILIZER KEY COLLATION
BASIC INSPECTION.

1

Work

Before performing the diagnosis, perform basic inspection. Refer to TELEMATICS SYSTEM
(DIAGNOSTICS)>General Description>INSPECTION
NOTE:
- Check the battery and its installation condition.
- Check the related fuse. Refer to WIRING SYSTEM>Telematics System>WIRING DIAGRAM
- Visually check that the related connectors are properly connected.
Also, check the related ground terminal for looseness and corrosion.

Check

Is the check result OK?

Yes

Go to 2.

No

Repair the defective part.
After the repair, go to 5.

CAUTION: VEHICLE SERVICING PERFORMED BY UNTRAINED PERSONS COULD
RESULT IN SERIOUS INJURY TO THOSE PERSONS OR TO OTHERS.
Subaru Service Bulletins are intended for use by professional technicians ONLY. They
are written to inform those technicians of conditions that may occur in some vehicles,
or to provide information that could assist in the proper servicing of the vehicle. Properly
trained technicians have the equipment, tools, safety instructions, and know-how to
do the job correctly and safely. If a condition is described, DO NOT assume that this
Service Bulletin applies to your vehicle, or that your vehicle will have that condition.

Subaru of America, Inc. is
ISO 14001 Compliant
ISO 14001 is the international standard for
excellence in Environmental Management
Systems. Please recycle or dispose of
automotive products in a manner that is friendly
to our environment and in accordance with all
local, state and federal laws and regulations.

Continued...
Bulletin Number: 18-226-25R; Revised: 06/09/25

Page 1 of 3

2

CHECK DTC.
1. Turn the ignition switch to ON.
Work

2. Read the DTC of [Telematics] using the Subaru Select Monitor. Refer to TELEMATICS SYSTEM
(DIAGNOSTICS)>Diagnostic Trouble Code (DTC)

Check

Is DTC B2A16 displayed? (Current code)

Yes

Go to 3.

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

3

CHECK DCM POWER SUPPLY.
Work

Using the Subaru Select Monitor, check the following items in the [Data monitor] of [Telematics]. Refer to
TELEMATICS SYSTEM (DIAGNOSTICS)>Data Monitor.
• Battery voltage

Check

Is the voltage 9 - 16 V?

Yes

Go to 4.

No

Replace the battery and go to 4.
Refer to STARTING/CHARGING SYSTEMS(H4DO)>Battery.

4

PERFORM IMMOBILIZER SYSTEM RE-REGISTRATION.

Work

Perform re-registration of immobilizer system for DCM using the Subaru Select Monitor. Refer to the
“REGISTRATION MANUAL FOR IMMOBILIZER” for more details.
NOTE:
“Telematics CM,” described in “REGISTRATION MANUAL FOR IMMOBILIZER”, is described as “DCM” in the
Service Manual.

Check

Is registration complete?

Yes

Go to 5.

No

Refer to “Correspondence table when registration is not possible” in the “REGISTRATION MANUAL FOR
IMMOBILIZER.”

5

CHECK DTC.

Work

1. Cycle the ignition Off and wait 1 minute.
2. Turn ignition on clear all DTCs
3. Cyle ignition off and wait 1 mintue.
4. Turn ignition on Read the DTC of [Telematics] using the Subaru Select Monitor. TELEMATICS SYSTEM
(DIAGNOSTICS)>Diagnostic Trouble Code (DTC).

Check

Is DTC B2A16 displayed?

Yes

Replace the DCM. Refer to ENTERTAINMENT & MONITORING>Data Communication Module.

No

Go to 6.

Continued...
Bulletin Number: 18-226-25R; Revised: 06/09/25

Page 2 of 3

6

CHECK DTC.
Work

Turn ignition on using the Subaru Select Monitor, read the value of Immobilizer Key Registration Status

Check

Is the Value of [Immobilizer Key Registration Status] Registered?

Yes

Go to 7.

No

Go to 4.

7

CHECK DTC.
Work

Test all function of telematics system

Check

Is the telematics system working as designed

Yes

Function returned to normal.

No

Go to 1.

Note: For in-depth testing of telematics functions and operations, refer to TSB 15-266-20R.
IMPORTANT REMINDERS:
• SOA strongly discourages the printing and/or local storage of service information as previously
released information and electronic publications may be updated at any time.
•

Always check for any open recalls or campaigns anytime a vehicle is in for servicing.

•

Always refer to STIS for the latest service information before performing any repairs.

Bulletin Number: 18-226-25R; Revised: 06/09/25

Page 3 of 3