ATTENTION:
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PARTS MANAGER

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CLAIMS PERSONNEL

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IMPORTANT - All
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© 2020 Subaru of America, Inc. All rights reserved.

SERVICE BULLETIN
APPLICABILITY: 2018-22MY Legacy and Outback
2017-22MY Impreza
2018-22MY Crosstrek
2019-22MY Forester
2019-22MY Ascent
SUBJECT:

NUMBER: 16-132-20R
DATE: 12/18/20
REVISED: 07/22/21

Diagnostic Information for Alleged Chain Slip Condition
on TR580 / TR690 Transmissions

INTRODUCTION:
This Service Information Bulletin provides updated diagnostic procedures to follow and a brief
questionnaire to complete 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 completing the questionnaire located at the end of the Troubleshooting section, 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 required to submit a completed QMR which includes all Flow Chart
test results, SSM data and a COMPLETED copy of the questionnaire found on pg. 8. 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: 07/22/21

Page 1 of 11

Troubleshooting Flow Chart for Alleged CVT Chain Slip:

Chain slip** is occuring.
Replace the CVT Assy and TCM***
NOTES: ***SSM Data MUST be attached whenever submitting
reports for review. See table below for models requiring TCM
replacement in addition to CVT assembly replacement.

Model / TCM Replacement Y/N?
Legacy/Outback- 2.5L TR580: 20MY -

Y

2.4L DIT TR690: 20MY -

Y

Crosstrek- TR580: 20MY -

Y

Ascent- TR690: 19MY -

Y

All other Models / MYs

N

Engine and Primary Pulley
Speeds Overlap in this Graph
Gear Ratio

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 2 of 11

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: 07/22/21

Page 3 of 11

follow the Primary Pulley

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 4 of 11

Does
the condition
occur during up shift
(up ratio) or down shift (down ratio)?
FIG.55 for
See FIG.
FIG.44 & FIG.
FIG. 5
details.

FIG. 6

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 5 of 11

FIG. 5

Does the
condition occur right
before or after the lock-up operaFIG.77 for
tion? See FIG.
example.

Record and analyze the
Engine SSM data to determine
if the torque fluctuation is being
caused by the engine.
See
forFIG.
example.
See Fig.
FIG. 68 &
for
9 example.

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 6 of 11

FIG. 6

FIG. 7

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 7 of 11

FIG. 8

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.

FIG. 9

Bulletin Number: 16-132-20R; Revised: 07/22/21

Continued...
Page 8 of 11

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 9 of 11

Questionnaire for Alleged CVT Chain Slip Condition
Please use all applicable check boxes.
vehicle speed box.

Please enter a number value in

Please attach SSM data files for both before and after pre- and post-repair.
No.

Item

1

CVT Temperature

2

Location

3

Vehicle Speed

4

Condition:

Immediately after starting the engine
Highway

Vehicle Used for
Towing?

6

Frequency of Slip
Condition

7

How Long Has
Condition Been
Occurring?

Symptoms:

Warming-up

Paved-road

After warming-up

Rough-road
mph

Driving Condition

5

8

Answer

While accelerating

While decelerating
Yes

Only once

A few times

It just started

While cruising

No
Intermittent

Within the last month

Always
From new

Noise

Vibration

Shock/Bump

Hesitation/Surge

Shudder

Jerking/Bucking

Engine RPM rise/flare

Lack of power / not accelerate

Deceleration feeling

Engine RPM not rise

Engine RPM fluctuation / hunting gear

Other (please describe:)

T/M assy replacement

T/M part(s) replacement

AT relearn / torque converter relearn
9

Repair(s):

TCM Re-programing

No repair made (inspection only)

Other (please describe:)

Example: Satisfaction / dissatisfaction level, further improvement requirements.

10

Customer Comments Post-Repair:

Continued...
Bulletin Number: 16-132-20R; Revised: 07/22/21

Page 10 of 11

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: 07/22/21

Page 11 of 11