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Service bulletin SSM 53974

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11020049
Published by NHTSA2025-07-02
Manufacturer's numberSSM 53974
Manufacturer's date2025-06-24
NHTSA componentENGINE; POWER TRAIN
Manufacturer's systemA/C compressor belt

NHTSA's summary

Some 2024-2025 Mustang vehicles equipped with a 2.3L EcoBoost engine may require removal of the air conditioning compressor belt due to various concerns. Workshop Manual (WSM), Section 303-05 has been updated with improved removal and installation service procedure steps.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Transmission and driveline

Vehicles listed
FORD MUSTANG2024, 2025

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
20260942026-03-03. Engine
26V1220002026-03-03. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE)
20255492025-10-11. Engine
25V1640002025-03-14. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY
20243172024-06-04. Powertrain
24V3940002024-06-03. POWER TRAIN:CLUTCH ASSEMBLY:LINKAGE:HYDRAULIC HOSE/FITTINGS

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
TSB 26-24082026-09-30. Service bulletin. This bulletin supersedes 26-2309. Reason For Update: update the Model section to remove Aviator 10R80, update the Parts list to add 3.3L to W520514-S440, and add L1MZ-7Z490-G valve body separator plate for Aviator. Some of the vehicles listed in the Model statement above may exhibit at least one of the following conditions: * Harsh 3-4, 4-5 upshifts * Harsh 5-3, 4-3 downshifts * Harsh reverse engagements These symptoms may be worse when cold. This may be due to the F clutch friction plates brinelling into the clutch and planetary container cylinder (7B177).
SSM 550722026-08-25. Service bulletin. Some 2025-2026 Mustang vehicles equipped with a 5.0L or 2.3L engine and built on 15-Aug-2025 and through 01-Dec-2025 may exhibit various drivability symptoms and/or have diagnostic trouble codes (DTC) stored in the powertrain control module (PCM) related to throttle/pedal position circuits. This may be caused by a spread terminal at the PCM connector. Inspect for loose fitting terminals at C1551B for 2.3L vehicles, and C175B on 5.0L vehicles. Refer to the appropriate Wiring Diagram Cells for circuit identification and wiring repair information. Wire terminal repair kit part DU2Z-14474-CA is recommended for this repair. Refer to Wiring Diagram, Cell 005 for repair procedures. For claiming, use causal part 14290 and labor operations 12651D, 12651D45 and 12651D45WR.
TSB 26-23092026-07-01. Service bulletin. This bulletin supersedes 26-2241. Reason For Update: update the parts list to correct the claim quantity of the part number JB3Z-4B496-B from 3 to 6. Some of the vehicles listed in the Model statement above may exhibit at least one of the following conditions: * Harsh 3-4, 4-5 upshifts * Harsh 5-3, 4-3 downshifts * Harsh reverse engagements These symptoms may be worse when cold. This may be due to the F clutch friction plates brinelling into the clutch and planetary container cylinder (7B177).
TSB 26-22632026-06-05. Service bulletin. This bulletin supersedes 26-2112. Reason For Update: add 2026 model year vehicles, update LV fluid XT-10-QLVC and CXT-10-LV6 description to add "Transfer Case Fluid 4WD Only", and update Step 4 to inspect/replace 7H351 and 7B177 outside of this article. Some of the vehicles listed in the Model statement above may exhibit at least one of the following conditions: - No upshift past second gear - Unable to achieve third gear ratio - Illuminated MIL with DTCs P0757 and P2701 This may be due to a damaged one-way clutch (OWC).
TSB 26-22102026-06-05. Service bulletin. Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: * Engine misfire condition * Illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P0301, P0302, P0303, and/or P0304 stored in the powertrain control module (PCM)
TSB 26-22412026-05-18. Service bulletin. This bulletin supersedes 25-2587. Reason For Update: update the Parts list to add the F-clutch friction plates HL3Z-7B164-D and the F-clutch steel plates PR3Z-7B164-A for the proper vehicle lines, replace the transfer case mounting bolt part number from W714288-S438 to W714288-S437, update the part number W720688-S439 quantity from 2 to 1, update the part number ML3Z-7869-C claim quantity from 2 to 1 (only if necessary), update the description of CXT-10-LV6 and XT-10-QLVC by adding "transfer case fluid, 4WD only", move HL3Z-7A191-B and L1MZ-7F396-A fluid pan gaskets to the parts to inspect and replace list, and remove TL1Z-6775-A self adhesive heat shield from the F-150/Expedition/Navigator parts list as it is not a discard item. Some of the vehicles listed in the Model statement above may exhibit at least one of the following conditions: * Harsh 3-4, 4-5 upshifts * Harsh 5-3, 4-3 downshifts * Harsh reverse engagements These symptoms may be worse when cold. This may be due to the F clutch friction plates brinelling into the clutch and planetary container cylinder (7B177).
SSM 547192026-04-10. Service bulletin. For 20212026 vehicles equipped with the 10R80 transmission, a new Transmission Clutch Circuit Leak Test has been introduced in the Ford Diagnosis and Repair System (FDRS). This test utilizes the pressure and vacuum transducer (PVT) when available. When referred to a specific clutch (A-F) test by a pinpoint test in Workshop Manual (WSM), Section 307-01 > Diagnosis and Testing, the Clutch Assembly tests have been updated with a hyperlink to the new Transmission Line Pressure Test - Pressure Vacuum Transducer (PVT) Is Available procedure in WSM, Section 307-01 > General Procedures. This procedure provides instructions to perform the FDRS Transmission Clutch Circuit Leak Test when applicable. The new test improves the accuracy of detecting leaks within transmission fluid circuits and replaces the previous air check method. The previous air check procedure has been shown to produce a high rate of false positives, which may lead to unnecessary repairs when no actual leak is present. Accordingly, the air check procedure is not to be used for diagnosing internal transmission hydraulic leaks or as justification
SSM 546742026-04-06. Service bulletin. For 2021-2026 vehicles equipped with the 10R80 transmission, a new Transmission Clutch Circuit Leak Test has been introduced in the Ford Diagnosis and Repair System (FDRS). This test utilizes the pressure and vacuum transducer (PVT) when available. The Workshop Manual (WSM) has been updated under Section 307-01 > Diagnosis and Testing to include this procedure. The new test improves the accuracy of detecting leaks within transmission fluid circuits and replaces the previous air check method.
ECG2-25.2.8.5 Mustang2026-03-31. Over-the-air update. "26C10 Recall remedy -Addresses instances where the trailer lights and trailer brakes may not function"
TSB 26-21122026-03-23. Service bulletin. This bulletin supersedes TSB 26-2059. Reason For Update: To add missing labor operations. Some of the vehicles listed in the Model statement above may exhibit at least one of the following conditions: - No upshift past second gear - Unable to achieve third gear ratio - Illuminated malfunction indicator lamp (MIL) with DTCs P0757 and P2701 This may be due to a damaged one-way clutch (OWC).