Service bulletin 21B55

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)
Type	Service bulletin
NHTSA id	10201644
Published by NHTSA	2021-09-30
Manufacturer's number	21B55
Manufacturer's date	2021-09-10
NHTSA component	POWER TRAIN

NHTSA's summary

Certain 2021 and 2022 Model Year Bronco Sport, Maverick, Escape, Corsair, Edge, and Nautilus equipped with an 8F35 Transmission Automatic Transmission Fluid Level Check; In some of the affected vehicles, the transmission may have been over filled with transmission fluid. Transmission that are overfilled may result in likelihood of transmission fluid aeration, degraded shift quality in the vehicle, accelerated wear on bushings and bearings, and reduced cooling in the transmission.

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

Transmission and driveline

Vehicles listed
FORD BRONCO SPORT	2021
FORD EDGE	2021
FORD ESCAPE	2021
FORD MAVERICK	2022
LINCOLN CORSAIR	2021
LINCOLN NAUTILUS	2021

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

Recalls for the same vehicles and component
25V881000	2025-12-18. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
25V158000	2025-03-14. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM
2025108	2025-03-02. Powertrain
25V133000	2025-02-28. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
25V127000	2025-02-28. ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
24V590000	2024-08-09. ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
2024270	2024-05-10. Powertrain
24V330000	2024-05-10. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
24V267000	2024-04-12. ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)
2021011	2021-01-18. Powertrain

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
SSM 55221	2026-10-12. Service bulletin. For 20222026 vehicles equipped with a 8F35 transmission, a revision to the Road Testing Vehicle procedure has been made in the WSM, Section 307-01 > Diagnosis and Testing. This updated procedure improves the diagnosis of customer reported transmission concerns and aids in locating the proper root cause. During diagnosis and testing, details regarding whether the condition is more prevalent when the vehicle is hot or cold, throttle percentage at the time of occurrence, vehicle speed, the specific shift involved, and whether the issue occurs during transmission engagements (N>R, N>D, R>D, and/or D>R) should be noted in the warranty claim. Engineering requests including these detailed operating conditions that will significantly assist with root cause analysis. Diagnosis, testing, and repair should use established labor times outside this article.
TSB 26-2341 v2	2026-10-01. Service bulletin. This bulletin supersedes 26-2171. Reasons for update: update the Parts list to add a note to clarify the application of the part numbers W520102-S442 and 4S4Z-3N324-AA "FWD Only". Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: Shudder condition, most noticeable at speeds below 60 mph (100 km/h) No relevant diagnostic trouble codes (DTC) present Traceable shudder event with IDS/FDRS reading (Figure 1) This condition may be perceived/felt as an engine misfire. This may be due to a concern with the output planetary assembly.
TSB 26-2341	2026-07-27. Service bulletin. This bulletin supersedes 26-2171. Reasons for update: update the Parts list to add a note to clarify the application of the part numbers W520102-S442 and 4S4Z-3N324-AA "FWD Only". Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: Shudder condition, most noticeable at speeds below 60 mph (100 km/h) No relevant diagnostic trouble codes (DTC) present Traceable shudder event with IDS/FDRS reading (Figure 1) This condition may be perceived/felt as an engine misfire. This may be due to a concern with the output planetary assembly.
TSB 26-2328	2026-07-20. Service bulletin. This bulletin supersedes 26-2194. Reason for update: update the Parts list to correct a part description " Loctite 638", update the claim quantity for the drain/fill plug, update the claim quantity of the wheel hub bolts (Corsair) and limited the parts list for Edge/Nautilus to only the rear drive unit fluid. Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: Shudder chatter condition, most noticeable at low speeds turning No relevant diagnostic trouble codes (DTCs) present This may be due to internal rear drive unit (RDU) fluid contamination.
SSM 54980	2026-07-08. Service bulletin. Some 2022-2024 Maverick Hybrid vehicles may exhibit an intermittent vibration and/or crunching noise after a cold start while the engine is running with the vehicle stationary in drive with no throttle input and brakes applied. An intermittent engine rocking or rolling motion in one direction may also be observed while the concern is present with the hood open. The noise may be present with no drivability concerns, relevant diagnostic trouble codes (DTC) stored, warning indicators illuminated and/or warning messages displayed. The noise may reduce or be eliminated after several minutes of driving when the powertrain warms up. This condition does not affect vehicle durability and no additional diagnosis or service is required for this condition at this time. Inform customers that they can continue to drive the vehicle and engineering is currently working on a solution for this condition that is expected in Q3 of 2026. Replacement of the engine or transmission will not resolve this condition. Monitor Professional Technician System (PTS) for additional information and schedule
SSM 54939	2026-06-22. Service bulletin. Some 2020-2026 Corsair/Escape, 2021-2026 Bronco Sport, and 2022-2026 Maverick vehicles equipped with an 8F35 transmission may exhibit a shudder condition, most noticeable at speeds below 60 mph (100 km/h), with no relevant diagnostic trouble codes (DTC) stored in the powertrain control module (PCM). Sometimes, this may be perceived/felt as an engine misfire. This may be due to the torque converter. If Pinpoint Test K: Torque Converter Clutch Operation in Workshop Manual (WSM), Section 307-01 > Diagnosis and Testing > Diagnosis by Symptom directs to replace the torque converter, remove and replace the torque converter and torque converter seal. Refer to WSM, Section 307-01 > Removal and Installation > Torque Converter Seal. Remove the main control valve body. Refer to WSM, Section 307-01 > Removal and Installation > Main Control Valve Body. Overhaul and thoroughly clean the main control valve body. Refer to WSM, Section 307-01 > Overhaul > Main Control Valve Body. Reverse the removal procedure to reassemble the transmission. Install the transmission. Refer to WSM, Section 307-01 > Installation. For claim
SSM 54797	2026-05-08. Service bulletin. Some 2020-2026 Corsair/Escape, 2021-2026 Bronco Sport, and 2022-2026 Maverick vehicles equipped with an 8F35 transmission may exhibit a shudder condition, most noticeable at speeds below 60 mph (100 km/h), with no relevant diagnostic trouble codes (DTC) stored in the powertrain control module (PCM). Sometimes, this may be perceived/felt as an engine misfire. This may be due to the torque converter. If Pinpoint Test K: Torque Converter Clutch Operation in Workshop Manual (WSM), Section 307-01 > Diagnosis and Testing > Diagnosis by Symptom directs to replace the torque converter, remove and replace the torque converter and torque converter seal. Refer to WSM, Section 307-01 > Removal and Installation > Torque Converter Seal. Remove the main control valve body. Refer to WSM, Section 307-01 > Removal and Installation > Main Control Valve Body. Overhaul and thoroughly clean the main control valve body. Refer to WSM, Section 307-01 > Overhaul > Main Control Valve Body. Reverse the removal procedure to reassemble the transmission. Install the transmission. Refer to WSM, Section 307-01 > Installation.
TSB 26-2194	2026-04-28. Service bulletin. This bulletin supersedes 25-2627. Reason for update: To add a Step to reprogram the all-wheel drive (AWD) module for Bronco Sport vehicles. Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: Shudder chatter condition, most noticeable at low speeds turning No relevant diagnostic trouble codes (DTCs) present This may be due to internal rear drive unit (RDU) fluid contamination.
SSM 54615	2026-03-04. Service bulletin. Some 2020-2026 Escape and 2021-2026 Corsair vehicles equipped with a 2.5L engine may exhibit a fuel door that won't open with diagnostic trouble code (DTC) P04CA stored in the powertrain control module (PCM). This may be due to an open circuit on circuit SBB05 and/or a damaged splice S133. Before performing the pinpoint test for P04CA in Workshop Manual (WSM), Section 310-00, inspect circuit SBB05 and splice S133 for damage such as an open circuit. Repair as necessary. Refer to Wiring Diagram, Cell 005. If no damage is found, refer to WSM, Section 310-00 for normal diagnostics. For claiming use causal 14290 and labor operations 12650D, 12650D45, and 12650D45WR.
TSB 25-2627	2026-02-12. Service bulletin. This article supersedes TSB 25-2552 to update the Parts List Some of the vehicles listed in the Model statement above may exhibit all of the following conditions: Shudder chatter condition, most noticeable at low speeds turning No diagnostic trouble codes DTCs present This may be due to rear drive unit internal (RDU) fluid contamination.