16-132-20R

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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© 2020 Subaru of America, Inc. All rights reserved.
SERVICE BULLETIN
APPLICABILITY:
		
		
		
		
SUBJECT:
		
2018-21MY Legacy and Outback
2017-21MY Impreza
2018-21MY Crosstrek
2019-21MY Forester
2019-21MY Ascent
NUMBER: 16-132-20R
DATE: 12/18/20
REVISED: 12/29/20
Diagnostic Information for Alleged Chain Slip Condition
on TR580 / TR690 Transmissions
INTRODUCTION:
This Service Information Bulletin provides updated diagnostic procedures to follow when diagnosing
an alleged Chain Slip condition on the TR580 and TR690 model CVT transmissions used in the
models listed above. In some cases, the customer may have had a concern of hearing an abnormal
sound and / or felt an unusual vibration while driving. This information is intended to provide
Technicians a user-friendly procedure which will help to ensure an accurate diagnosis and reduce the
possibility of unnecessary CVT replacements.
SERVICE PROCEDURE / INFORMATION:
Customer satisfaction and retention starts with performing quality repairs.
After following the diagnostic procedures supplied in this bulletin and when determined necessary,
service procedures for CVT and / or TCM replacement remain unchanged. Always refer to the
applicable Service Manual and review the full requirements of the repair being performed. The
Service Manual procedures contain information critical to performing an effective repair the
first time, every time. This includes but is not limited to important SAFETY precautions, proper
inspection criteria, necessary special tools, required processes and related one-time-use parts needed
for a complete and lasting repair.
VERY IMPORTANT: With any customer concern, it is important to get a complete and detailed
description from them so their condition can be duplicated. Duplicating the condition is critical for
a proper diagnosis and successful repair. Whenever using this TSB for alleged CVT Chain Slip
diagnosis, Technicians are requested to submit a completed QMR which includes all Flow
Chart test results and SSM data. This information will be extremely helpful for SBR Engineers
when analyzing what the customer was experiencing as Chain Slip. Cooperation with this special
information request is greatly appreciated!
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: 16-132-20R; Revised: 12/29/20
Page 1 of 8
Troubleshooting Flow Chart for Alleged CVT Chain Slip:
NOTE: SSM Data MUST be attached
whenever submitting Report for review.
Engine and Primary Pulley
Speeds Overlap in this Graph
Gear Ratio
Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
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Engine Speed (rpm) Primary Pulley Speed (rpm)
Example screenshot of TCM PIDS with Front Wheel Speed and Secondary Revolution Speed
selected.
Engine Speed
Primary Pulley Speed
Secondary Pulley Speed
Front Wheel Speed
Gear Ratio
Times (s)
Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
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Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
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Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
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Record and analyze the Engine SSM data to determine if
the torque fluctuation is being
caused by the engine.
FIG.66 for example.
See Fig.
Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
Page 6 of 8
FIG. 6
The graph above is an example of recorded SSM data showing the torque fluctuation is
NOT being caused by the transmission but by torque fluctuation of the engine.
Continued...
Bulletin Number: 16-132-20R; Revised: 12/29/20
Page 7 of 8
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: 16-132-20R; Revised: 12/29/20
Page 8 of 8