Have a 2020-2024 outback? 2022-2025 wilderness? Transmission jerking or a judder sensation felt from the powertrain during braking with the air conditioning on? Shudder is felt from the powertrain along with a screeching type of sound?
then this TSB might be for you!
What this thread is about:
Discussions found elsewhere that don’t belong in this thread:
NOTE: there is a recall for some 2.4L turbo transmission issues, but it’s a separate problem. See the recall thread here
Observations:
Summary of TSB 16-150-24R:
Revision History:
Oct 11, 2024 - thread created. Original TSB attached
Nov 17, 2024 - updated TSB attached. summary section updated with new date, and more model years affected
Dec 05, 2024 - attached TSB 16-151-24 for reference
Apr 07, 2025 - updated TSBs attached
then this TSB might be for you!
What this thread is about:
- The fact there is a TSB for this concern, and questions about those specific conditions
- Experiences getting this specific fix applied at a subaru service center
- Changes to the TSB over time - the official resolution, introduction of newer part numbers. If it's in the TSB, and is changed, it's fair game.
Discussions found elsewhere that don’t belong in this thread:
- 2020-2022 models: Shudder on turns under acceleration with the XT models, that is a DIFFERENT service bulletin and problem. This one isn't for you. Don't talk about that here, it won't help anyone. Talk about that over here where it might help someone.
- Chirp sound when shifting from park into drive or reverse. It’s part of the transmission design, a known issue, and has nothing to do with this bulletin. Go here if you want to know more or contribute
- Discussions around the recall WRK-21/22. Transmission reprogramming and the recall can be discussed in that thread, questions about it can be answered, or even contribute your experiences there.
- Replacing CVT fluid, or any other DIY service you want to perform. There are plenty of threads around that too, contribute there, make those threads better. Gen6 CVT fluid replacement.... Gen6 CVT Fluid Check.
- generally, anything that is not in the three bullet points in the “what this thread is about” heading above. If you want other conversation, start your own thread. Thanks!
NOTE: there is a recall for some 2.4L turbo transmission issues, but it’s a separate problem. See the recall thread here
Observations:
- The revised service bulletin EXTENDS the applicability back to the start of the model generation. Previously, it was 2023-2024 outbacks. Now it is 2020-2024 model years.
- Outback models will have a software reprogramming applied. If that fails, for whatever reason, a NEW TCM is put in the car.
- 2024 Wilderness model guidance has changed - previously, it was TCM replacement ONLY. Now, it's TCM replacement, followed by a check to see if the software is new enough to contain the countermeasures. The change is because the original TCMs could not be programmed due to a software incompatabilty, they required direct replacement. The change for verifying the installed software AFTER a hardware TCM replacement is because not all TCMs may have software revisions that include the required countermeasures. No part numbers given for known "good" TCM - verification must be performed after each TCM replacement.
- There is a chart for what VIN range is potentially affected, and for the Outback it is listed as TBD (to be determined).
- The graphic for the "judder sensation occurs" is epic.
- There is a NEW service bulletin that references this one, and several other similar issues, so it functions as a sort of lookup document, and has some interesting things in it. This is TSB 16-151-24R. It includes things from this service bulletin, and some other troubleshooting/diagnostic information. Worth a look. I attached it too.
Summary of TSB 16-150-24R:
Bulletin Number: 16-150-24R Date: 12/03/24 NUMBER: 16-150-24R APPLICABILITY: 2020-24MY Legacy 2.4L 2020-24MY Outback 2.4L 2019-24MY Ascent 2022-24MY WRX 2022-25MY Outback Wilderness SUBJECT: Transmission Control Module (TCM) / Software Enhancement INTRODUCTION: This bulletin announces availability of new reprogramming files developed to address the two symptoms described below: SYMPTOM 1: A jerk or judder sensation felt from the powertrain during braking with the air conditioning on. SYPMTOM 2: A shudder is felt from the powertrain along with a screeching type of sound. NOTE: Both of these symptoms are not related with a fault code. The new files contain enhanced software optimizing input clutch application along with enhanced hydraulic pressure control during braking/deceleration. On some model applications, the Transmission Control Module (TCM) will require replacement along with a final reprogramming (if applicable). If a customer reports either of the symptoms described above and their vehicle is within the VIN range listed below, follow the procedures outlined within this bulletin. Model - Starting VIN Outback - TBD Legacy - N/A Ascent - R3439833 WRX - R8807951 |
Revision History:
Oct 11, 2024 - thread created. Original TSB attached
Nov 17, 2024 - updated TSB attached. summary section updated with new date, and more model years affected
Dec 05, 2024 - attached TSB 16-151-24 for reference
Apr 07, 2025 - updated TSBs attached