Labor Time:

CVT Diagnosis

B303986

0.6

See Labor Operations per Flow Chart Used
Diagnosis and No Fault Found/QMR Submitted

C303386

Fail Code

MKO-00
0.2

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.
Continued...

Bulletin Number: 16-151-24; Date: 10/22/24

Page 9 of 22

APPENDIX A (Section 1)
IMPORTANT: 2023MY Legacy & Outback 2.4L vehicles, refer to TSB 16-145-23R.
Function of “Gear Ratio Change Rate Error Judgement”
Description: When feeling shocks or vehicle body vibrations during acceleration, this function will
support the diagnostic process to determine whether a chain slip occurs in the CVT or not.
Precautions for road testing:
•

Use a USB cable to connect the DST-i or DST-010 to a PC. Wireless communication may lead
to a wrong determination

•

When driving on public roads, pay attention to the surrounding traffic conditions and drive
safely incompliance with the law.

•

To ensure accurate detection of abnormal gear ratio changes, please refrain from the following
actions during the test drive:
○ Sudden deceleration or acceleration
○ Driving on rough roads
○ Driving the vehicle with the four wheels not stably contacting the ground, such as driving
over bumps and/or putting the vehicle on lift before completing the detection process.

SSM Workflow
1. On the [Start] screen, select [Diagnosis].
2. On the [Select Vehicle] screen, enter the vehicle information and select [Confirm].
3. On the [Main Menu] screen, select [Each System].
4. On the [Select System] screen, select [Transmission].
5. On the [Select Function] screen, select [Work Support].
6. On the [Work Support] screen, select [Gear Ratio Change Rate Error Judgement].
7. Follow the instruction displayed on the screen and perform a road test.
8. Once the concern is replicated, end the testing and the results will automatically populate.
When the message “Gear Ratio Change Rate Error Judgment is Complete” is displayed, the
detection process has finished. Testing automatically ends after a time period approximately
50 minutes. If an additional measurement is desired, restart the Subaru Select Monitor after
saving the data.
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Bulletin Number: 16-151-24; Date: 10/22/24

Page 10 of 22

Road Test Pattern:
No.

Accelerator Opening
Degree

Vehicle Speed

1

30%

0  30mph

2

50%

0  30mph

3

100%

0  30mph

4

After driving at a constant
speed for 20s at the vehicle
speed shown on the right,
accelerate by stepping on
the accelerator opening
10% more.

30(constant speed) 
40mph
40(constant speed) 
50mph
50(constant speed) 
60mph

5
6

Number Of Times
Implemented

Note

Each 1 time

If the customer’s
suggestions are specific,
such as vehicle speed
and accel pedal opening,
implement that driving
pattern.

Continued...
Bulletin Number: 16-151-24; Date: 10/22/24

Page 11 of 22

APPENDIX A (Section 2)
Lockup Judder Type A Diagnosis Procedure.
CAUTION: Confirm WRK-21/22 Has Previously Been Performed.
After the test drive has been completed with replication of the symptom, refer to the judgement
criteria and example graph below to determine if the condition matches Lockup Judder Type A. If
replication has not been completed, refer to the replication steps below.

Replication Method
STEP 1: Warm up the CVT until CVTF temperature reaches 122-158 degrees F (50-70 degrees C).
STEP 2: Make a complete stop, then accelerate the vehicle with throttle opening of approx. 15%.
STEP 3: As soon as the lockup operation begins at around 13mph with a slight drop of engine speed,
open the throttle further to 25% quickly.
STEP 4: Repeat the Step 2 and 3, 10 (ten) times.
STEP 5: In case a when a judder sensation is felt, the vehicle is presenting .

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 12 of 22

APPENDIX A (Section 2)
Lockup Judder Type B Diagnosis Procedure:
After the test drive has been completed with replication of the symptom, refer to the judgement
criteria and example graph below to determine if the condition matches Lockup Judder Type B. If
replication has not been completed, refer to the replication steps below.

Replication Method
STEP 1: Warm up the CVT until CVTF temperature reaches 68-122 degrees F (20-50 degrees C).
STEP 2: Make a complete stop, then accelerate the vehicle with constant throttle opening of 15-20%.
STEP 3: Repeat the Step 2, 10 (ten) times.
STEP 4: In a case when a judder sensation is felt, the vehicle is presenting .

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 13 of 22

APPENDIX A (Section 3)
Forward Clutch Judder Diagnosis Procedure:

Examples Graph for Forward Clutch Judder:

Replication Method
STEP 1: Warm up the CVT until CVTF temperature reaches 104-140 degrees F (40-60 degrees C).
STEP 2: Using Eyesight Adaptive Cruise Control (without using gas pedal,) drive the vehicle at 5060mh for more than 7 (seven) miles.
STEP 3: Turn the Eyesight Adaptive Cruise Control off and keep constant speed of 40-60mph using gas
pedal.
STEP 4: Depress gas pedal to increase throttle opening by 3-4% per second up to 30%.
STEP 5: Repeat Step 3 and Step 4 10 (ten) times.
STEP 6: In a case when a judder sensation is felt, the vehicle is presenting < Forward Clutch Judder >.
Continued...
Bulletin Number: 16-151-24; Date: 10/22/24

Page 14 of 22

APPENDIX A (Section 4)
A jerk or judder sensation felt from the powertrain during braking
with the air conditioning on.
IMPORTANT: 2023-24MY Legacy & Outback 2.4L, 2023-24MY Ascent, and 2023-24MY WRX
vehicles, refer to TSB 16-150-24

For vehicles within the Basic New Car Limited Warranty period or covered by an active Subaru
Added Security Classic or Gold plan, this repair may be submitted using the following claim
information:
Labor Description

Labor Operation #

Labor Time:

Fail Code

TRANSMISSION CONTROL MODULE
REPROGRAMMING

B860-686

0.5

MJZ-48

TRANSMISSION CONTROL MODULE R&R
INCLUDING RELEARN

B860-786

0.8
MJT-43

TCM UPDATE AFTER REPLACEMENT

C860-118

0.3

Continued...
Bulletin Number: 16-151-24; Date: 10/22/24

Page 15 of 22

APPENDIX A (Section 5)
Noise and/or Judder While Turning Symptom Diagnosis Procedure:
NOTE: The noise/vibration typically occurs under cold conditions.
STEP 1: With the SSM connected confirm the CVT temperature is below 176 degrees F (80C) before
driving to collect data. If 176F (80C) or above, let the CVT cool before evaluating it.
STEP 2: Confirm if the noise/vibration appears by driving the vehicle under the conditions below.
Pay full attention when performing a road test. Conducting the road test in closed area and with an
additional person is recommended.
Items

Conditions

CVT oil pan temperature

Up to 176Deg F*

Accelerator opening angle

10 to 30%

Steering angle

Full Steer

Vehicles speed

Under 20mph

NOTE: *The noise/vibration may not occur when the CVTF temperature is higher than 176 degrees
F (80 C).
Countermeasure Service Procedures:
Lockup Judder Type A & B: Torque Convertor (p.n. 31100AB460) replacement, CVT Fluid (p.n.
31333AA160) replacement, and TCM software reprogramming (newest software available).
Forward Clutch Judder: CVT Fluid (p.n. 31333AA160) replacement and TCM software
reprogramming (newest software available).
Noise and/or Judder While Turning Symptom: TCM software reprogramming (newest software
available). Replacement of the referenced parts below. See the tables below for applicability.
LEGACY & OUTBACK

ASCENT & OUTBACK WILDERNESS

Part Description

Part Number

Qty

Part Description

Part Number

Qty

CLUTCH ASSY-TRF

33119AA740

1

CLUTCH ASSY-TRF

33119AA720

1

THRUST BEARING

806536020

806536020

806535030

806535030

806535040

806535040

806535050

1*

THRUST BEARING

806535050

806535060

806535060

806535070

806535070

806535090

806535090

1*

GASKET

803916010

1

GASKET

803916010

1

GASKET

803918060

1

GASKET

803918060

1

RING-SEAL

31377AA490

3

RING-SEAL

31377AA490

3

High Torque CVT-LV (As Needed)

High Torque CVT-LV (As Needed)

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 16 of 22

Model

Transmission Fluid

ALL

High Torque CVTF-LV

Part Number

Quantity/Unit/Pack

SOA748V0300

5 Gallon Pail

SOA748V0310

16-Gallon Keg

Warranty Part #
SOA635312

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 17 of 22

APPENDIX B: (INFORMATIONAL PURPOSES ONLY)
CVT Chain Slip Diagnosis Procedure:
There are three main forms of CVT chain slip.
1. Continuous Micro-Slip
2. Short-Time Slip
3. Long-Time Slip
Using Subaru Select Monitor (SSM), check and record data monitors and compare to the three
examples listed below. If the recorded data from the vehicle matches the examples below, the CVT
will require replacement. The SSM data will be required for claim submission. A QMR containing the
same information will also be required.
1. Continuous Micro-Slip

Examples of the data monitoring during Continuous Micro-Slip:

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 18 of 22

2.

Short-Time Slip

When a short-time slip occurs, the changes in the Actual Gear Ratio monitor will be larger than 0.1
per 0.1 second. After the Actual Gear Ratio monitor resumes to stable conditions, distinct fluctuations
in revolution speed continues.
Example Graph of Short Time Slip:

3.

Long-Time Slip

When a long-time slip occurs, the Primary UP Duty monitor will be larger than 90% and the Actual
Pulley Ratio monitor lowers for a duration of 0.5 seconds or more. Even after the Actual Gear Ratio
monitor resumes to stable conditions, distinct fluctuations in revolution speed continues.

Continued...
Bulletin Number: 16-151-24; Date: 10/22/24

Page 19 of 22

REFERENCE MATERIAL:
Symptoms Similar to CVT Chain Slip:
1. Forward Clutch Slip Shock
This shock can occur when the forward clutch slips. If this situation is reported, reprogram the TCM
with the newest software available.
The rotation speeds for the upstream and downstream sides of the forward clutch do not synchronize
when driving.
Example for
2.4L Turbo or 3.6L NA equipped vehicles
Upstream side of the forward clutchSecondary Rev Speed
Downstream side of the forward clutchFront Wheel Speed

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 20 of 22

2. Lock Up Clutch Engagement Shock:
This shock can occur when the lock up engages rapidly. If this situation is reported, reprogram the
TCM with the newest software available.

3. Shift Up Shock:
This shock can occur when the CVT upshifts. If this situation is reported, reprogram the TCM with
new software if it is available. If there is no new software available or the reprograming does not
remedy the issue, report the situation to Techline.

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Bulletin Number: 16-151-24; Date: 10/22/24

Page 21 of 22

4. Primary Up Duty Square Control (Ascent Models up to 2021MY):

A harsh shift can be felt while driving. If this situation is reported, reprogram the TCM with new
software if it is available. If there is no new software available or the reprograming does not remedy
the issue, report the situation to Techline.

Bulletin Number: 16-151-24; Date: 10/22/24

Page 22 of 22