ATTENTION:
GENERAL MANAGER q
PARTS MANAGER

q

CLAIMS PERSONNEL q
SERVICE MANAGER

q

IMPORTANT - All
Service Personnel
Should Read and
Initial in the boxes
provided, right.

© 2017 Subaru of America, Inc. All rights reserved.

SERVICE INFORMATION BULLETIN
APPLICABILITY:
SUBJECT:

NUMBER: 07-108-16R

2014-2018MY Forester
Revised Diagnostic Procedure for DTC B1650

DATE: 04/18/16
REVISED: 08/22/18

INTRODUCTION:
This Service Information Bulletin provides a revised troubleshooting procedure and tips to follow
when diagnosing a DTC B1650- “Occupant Classification System Malfunction”. This DTC may
also be accompanied by B1760, B1761, B1771 or B1795 as found in the Occupant Detection control
module. The new procedure is designed to help avoid unnecessary part (seat cushion assembly)
replacements.
SERVICE PROCEDURE / INFORMATION:
IMPORTANT NOTES:
•

The SSMIII (NOT SM4) must be used to diagnose the Occupant Detection System (ODS) .
This requirement will remain until the January 2018 SM4 update is released. See table below.

Control Unit

DTC

Air Bag

B1650

ODS

B1760

ODS

B1771

ODS

B1795

•

DTC Timing
Current
Past
Current
Past
Current
Past
Current
Past

SSM4
(DTC display-capable)
Yes
Yes
Yes
No
Yes
No
Yes
No

SSM3
(DTC display-capable)
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

BEFORE proceeding with diagnosis of any ODS-related DTC. Always check to see if the
passenger seat cushion is wet, contains moisture or has been exposed to excessively humid
conditions for some time.

Continued...
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.

Bulletin Number: 07-108-16R; Revised 08/22/18

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.

Page 1 of 4

•

If any moisture is confirmed, the cushion must be completely dried See procedures supplied
later in this bulletin.

•

It is VERY IMPORTANT to understand the occupant detection sensor mat is a sensitive
component. For that reason, NEVER use a heat gun or a hair dryer in an attempt to “force
dry” the seat cushion.

A “temporarily” wet seat cushion resulting from (as examples) a window being inadvertently
left open during rainfall or possibly spilled food / drink possibly with a resulting clean-up using
water and / or cleaning liquids can cause moisture to be left behind and B1650 (or a related
DTC) to set. This is the most common scenario and what can easily lead to an unnecessary
seat cushion replacement.
It is VERY IMPORTANT to thoroughly review this information with the customer during the
Service write-up interview. Attempt to determine if this is an actual concern with the system or
if outside influence (moisture) may well be the root cause of the condition BEFORE proceeding
with further diagnosis or ordering any parts. Use the Owner’s Manual wording as an additional
reference for any discussions with the customer. If the memory is cleared and the seat cushion
is not thoroughly dry, the code will likely reset once someone sits in the seat again. In this case,
the system is operating as designed. If the seat is dry and the code is still current (not past), there
may be a damaged component or connection causing the DTC.
DRYING PROCEDURES:
If the passengers’ seat cushion is found wet or displays any staining, dry the seat cushion completely
using natural air. Parking the vehicle in a sunny spot with windows slightly open is recommended.
If necessary to speed the drying time, it is recommended to use the vehicle’s Air Conditioner
function:
•
•
•
•
•

Park the vehicle in open area or use exhaust ventilation equipment
Set the parking brake and start the engine
Turn the A/C ON, set the blower fan to MAX, then direct airflow from the vents at the seat
cushion
Set A/C temperature to a comfortable room temperature (full heat is not required).
Check the seat after some time to confirm it is fully dried.

REMINDER: The occupant detection sensor mat is a sensitive part. Use of a Hair Dryer or Heat Gun
to dry the seat cushion is not allowed.
The following screen shot samples show the REVISED diagnostics which will be incorporated into
the 2014MY and later Forester Service Manuals soon. The revised text is in red. This diagnostic
flow must be followed anytime the above listed vehicles present with B1650, B1760, B1761, B1771,
B1795 or any combination of these codes. Always record the step by step results for this diagnosis.

Continued...
Bulletin Number: 07-108-16R; Revised 08/22/18

Page 2 of 4

Step
1. CHECK DTC.
Read the DTC of the occupant detection
system.
2. CHECK POOR CONTACT OF
CONNECTORS.
Check for poor contact of the connectors
between the occupant detection control
module
and airbag control module.
3. CHECK AIRBAG REAR HARNESS.
1) Turn the ignition switch to OFF,
disconnect the battery ground cable,
and wait for 60 seconds or more.
2) Disconnect the connectors (AB59) and
(AB53) under the passenger’s seat.
3) Disconnect the connectors (AB6,
AB17, AB18) from the airbag control
module, and connect the connector
(1AG) in the test harness AG to
connectors (AB6, AB17, AB18).
4) Connect the connector (1AP) in the
test harness AP to the connector
(AB53).
5) Measure the resistance between
connector (6AG) in the test harness
AG and connector (2AP) in the test
harness AP.
Connector & terminal
(6AG) No. 9 — (2AP) No. 1:
(6AG) No. 11 — (2AP) No. 2:
4. CHECK AIRBAG REAR HARNESS.
Measure the resistance between
connector (6AG) in the test harness AG
and chassis ground.
Connector & terminal
(6AG) No. 9 — Chassis ground:
(6AG) No. 11 — Chassis ground:
(6AG) No. 9 — (6AG) No. 11:
5. CHECK OCCUPANT DETECTION
HARNESS.
1) Turn the ignition switch to ON.
2) Measure the voltage between
connector(2AP) in the test harness AP
and chassis ground.
Connector & terminal
(2AP) No. 3 (+) — Chassis ground (–):

Check
Are any of DTC
B1760, B1761,
B1771 and B1795
detected?
Is there poor
contact?

Yes
Perform the diagnosis
according to DTC.

No
Go to step 2.

Reconnect the connector. Go to step 3.
If condition is not
improved, replace the
Right Hand (RH) rear
body harness.

Is the resistance
less than 10 Ω?

Go to step 4.

Replace the RH
rear body harness.

Is the resistance
1 MΩ or more?

Go to step 5.

Replace the RH
rear body harness.

Is the voltage 10
V or more?

Go to step 6.

Check the battery
voltage and fuse.
If there is no fault,
replace the RH
rear body harness.

Continued...
Bulletin Number: 07-108-16R; Revised 08/22/18

Page 3 of 4

Step
6. CHECK AIRBAG SYSTEM DTC.
1) Turn the ignition switch to OFF.
2) Reconnect the disconnected
connector.
3) Turn the ignition switch to ON.
4) Read Airbag System current DTC.

Check
Is DTC B1650
detected?

Yes
If the condition is not
improved, replace the
occupant detection
system (passenger
side cushion & frame
assembly).
If the condition is still
not improved, then
replace the airbag control
module.

No
The system is
currently normal.
Check if any other
DTC is detected. If
there is no current
DTC, perform
Clear memory.

REFER TO THE LABOR TIME GUIDE ON SUBARUNET FOR APPLICABLE CLAIM
CODING INFORMATION.
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: 07-108-16R; Revised 08/22/18

Page 4 of 4