07-83-14

ATTENTION:
GENERAL MANAGER
PARTS MANAGER
CLAIMS PERSONNEL
SERVICE MANAGER
q
q
q
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IMPORTANT - All
Service Personnel
Should Read and
Initial in the boxes
provided, right.
SERVICE INFORMATION
APPLICABILITY:	All 2014-15MY Forester, Impreza, XV Crosstrek
2015MY WRX & STI Models
SUBJECT:
NUMBER: 07-83-14
DATE: 03/12/14
Diagnostics for DTC B1500 and U1500
INTRODUCTION
This bulletin provides information currently missing from the Service Manual for diagnosing Body
Integrated Unit (BIU) DTCs B1500 and U1500 (Keyless UART Communication Malfunction on
the push-button start vehicles) as listed above. Diagnostics are included in the current version of
the Service Manual for DTC U1500 but only for key-start vehicles. The Service Manuals will be
updated to include this information in the near future.
IMPORTANT NOTE: DTC U1500 is only applicable to 2015 WRX & STI Models while B1500 is
only applicable to 2014-15MY Forester, Impreza, XV Crosstrek (including Hybrid model).
(UART= Universal Asynchronous Receiver Transmitter)
SERVICE PROCEDURE / INFORMATION
• Information and diagnostic steps contained in the RED boxes are applicable to DTC U1500.
STEP
CHECK
YES
NO
1 CHECK DTC.

1) Insert the ignition key to the ignition
key cylinder and remove.
2) Read the DTC of body integrated unit
using Subaru Select Monitor.

Is B1500 current
malfunction?
Is U1500 current
malfunction?
Go to step 2.
Go to step 7.
1) Carry the access key in the vehicle
and push the start button twice
without depressing the brake pedal
to turn the ignition switch to ON.
2) Read the DTC of body integrated
unit using Subaru Select Monitor.
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: 07-83-14; Date: 03/12/14
SUBARU OF AMERICA, INC. IS
“ISO 14001 COMPLIANT”
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.
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STEP
CHECK
YES
NO
2 CHECK DTC.

1) Turn the ignition switch to OFF.
2) Disconnect the body integrated unit
and keyless entry control module
connector.
3) Connect the disconnected connectors.
4) Insert the ignition key to the ignition
key cylinder and remove.
5) Read the DTC of body integrated unit
using Subaru Select Monitor.

1) Turn the ignition switch to OFF.
Is B1500 current
malfunction?
Is U1500 current
malfunction?
Go to step 3.
Go to step 7.
Go to step 4.
Repair the open
circuit of harness
or replace
harness.
2) Disconnect the body integrated
unit and keyless entry control
module connector.
3) Connect the disconnected
connectors.
4) Carry the access key in the vehicle
and push the start button twice
without depressing the brake pedal
to turn the ignition switch to ON.
5) Read the DTC of body integrated
unit using Subaru Select Monitor.
3 CHECK HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the body integrated unit
and keyless entry control module
connector.
3) Using the tester, measure the
resistance between terminals.
Connector & terminal
With TPMS
Is the resistance
10 Ω or less?
(i171) No. 11 — (R221) No. 11:
Without TPMS
(i171) No. 11 — (R80) No. 3:
Continued...
Bulletin Number: 07-83-14; Date: 03/12/14
Page 2
STEP
CHECK
YES
NO
4 CHECK HARNESS.

1) Turn the ignition switch to OFF.
2) Use a tester to measure the voltage
between the terminals.
Connector & terminal
With TPMS
(R221) No. 6 (+) — Chassis ground (–):
Without TPMS
(R80) No. 4 (+) — Chassis ground (–):

Is the voltage 10 V
or more?
Go to step 5.
Repair the power
supply circuit.
Is the resistance
10 Ω or less?
Go to step 6.
Repair the
ground circuit.
1) Carry the access key in the vehicle
and push the start button twice
without depressing the brake pedal
to turn the ignition switch to ON.
2) Turn the ignition switch to ON.
3) Use a tester to measure the
voltage between the terminals.
Connector & terminal
With TPMS
(R221) No. 4 (+) — Chassis ground (–):
5 CHECK HARNESS.
Using the tester, measure the resistance
between terminals.
Connector & terminal
With TPMS
(R221) No. 5 — Chassis ground:
Without TPMS
(R80) No. 7 — Chassis ground:
6 CHECK CONTROL MODULE.
1) Turn the ignition switch to OFF.
2) Remove the keyless entry control
module.
3) Install a keyless entry control module
that was operating normally on
another vehicle.
7 CHECK CONNECTOR.
Check the connector used for keyless
communication for poor contact.
Bulletin Number: 07-83-14; Date: 03/12/14
Does it operate
with the remote
control key of
another vehicle?
Is there poor
contact of
connector?
Replace the
keyless entry
control module.

Replace the body
integrated unit.
It is possible that
Repair the
temporary poor
connector that has
communication
poor contact, or
occurs. Delete
replace harness.
the DTC.
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