Volvo bulletin 36774.4.0
What it saysThis is a Technical Journal: Text plus 1 PDF -- DTC TCM P277C07 set. NHTSA’s full summary ↓
Volvo filed this with NHTSA as a service bulletin dated Sep 17, 2026, received Oct 5, 2026, about the power train. It names 12 model years (2024–2027). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis is a Technical Journal: Text plus 1 PDF -- DTC TCM P277C07 set. If the TCM DTC listed below is set, A new transmission hardware solution has been introduced starting from transmission serial number 25M8L30144, which serves as a defined break point for updated production. *If the DTC is confirmed and the transmission serial number is after the break point: Do NOT replace the transmission follow the advise under "Service".
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 36774.4.0 | Service bulletin | Sep 17, 2026 | 11037965 |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 12 model years this bulletin names have filed 159 complaints with NHTSA since 2015. 5 of them name Power Train — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
On July 27, 2026, I was driving my 2026 Volvo XC90 T8 plug-in hybrid at approximately 70 mph on the highway with 2,160 miles on the odometer. Without warning, a turtle-mode indicator illuminated and the vehicle's speed was electronically limited, dropping from 70 mph to approximately 50 mph while in moving traffic.
2026 Volvo XC90 · Power Train · filed with NHTSA Sep 18, 2026 · ODI 11765435
Some critical functions on the center display console instrument panel are freezing up while driving - we are unable to change the drive mode while the car is in motion. This has not happened before, and it is glitching a lot lately.
2024 Volvo XC90 · Power Train · filed with NHTSA Sep 15, 2025 · ODI 11687349
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the power train
Source: same model, same component group36 other manufacturer communications filed against these Volvo models under the same component group (power train), newest first. The eight newest are listed; the rest are on the Volvo list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 37504.3.0 | Service bulletin | Sep 19, 2026 | This is a TJ Text Only no attachment If a customer experiences a DIM message stating "Propulsion Service Required" and IEM P0A7A48 is stored… |
| 36894.5.2 | Service bulletin | Sep 9, 2026 | This is a Technical Journal: Long Range PHEV ERAD Knocking Noise Repair Kit. Install a repair kit. |
| 37871.1.0 | Service bulletin | Jul 11, 2026 | This is a TJ - Text only no attachments - During the first year in production of the new engines, with the updated transmission calibration… |
| 36774.3.0 | Service bulletin | Jun 10, 2026 | This is a Technical Journal: DTC TCM P277C07 set. If the TCM DTC listed below is set, A new transmission hardware solution has been introduc… |
| 36496.10.0 | Service bulletin | May 7, 2026 | This is a Technical Journal: Intermittent knocking noise during acceleration. If the sound corresponds to attached sound file, change front… |
| 37299 | Service bulletin | Feb 4, 2026 | This a Technical Journal plus 1 mp4 file If a customer experiences noise from the rear of the vehicle, often generated at low speeds and dur… |
| 37504 | Service bulletin | Dec 20, 2025 | This is a TJ Text Only no attachment If a customer experiences a DIM message stating "Propulsion Service Required" and IEM P0A7A48 is stored… |
| 37228 | Service bulletin | Dec 20, 2025 | This is a Technical Journal: Vehicle jerks in low speed when Start/Stop is active. Improved software is introduced from version 3.5.14. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Volvo, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Volvo 36774.4.0 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the 36774.4.0 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way.
Which vehicles does 36774.4.0 cover?
The manufacturer filed it against 12 model years: 2024 Volvo S60, 2026 Volvo S90, 2025 Volvo S90, 2024 Volvo S90, 2024 Volvo V60, 2026 Volvo XC40 and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.