2021 Subaru Ascent Technical Service Bulletins

384 technical service bulletins (TSBs) are on record for the 2021 Subaru Ascent. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11030561Mar 4, 2026Electrical system. This announcement provides information on the use of aftermarket services or tools for programming immobilizer keys/fobs.
• 11029347Feb 25, 2026Electrical system. This Service Information Bulletin was developed to provide interim guidance for 2026 model year vehicles exhibiting DTC B2A20 with gen 4 Telematics.
• 11029329Feb 6, 2026Electrical system. This bulletin announces the new procedure and Warranty Fail Code for FirstTime air conditioning (A/C) performance concerns possibly resulting from an undetected A/C refrigerant leak.
• 11027986Jan 15, 2026Electrical system. This Subaru service and technical support line newsletter provides information on the next phase of TechShare.
• 11027982Jan 12, 2026Engine, Electrical system. This Bulletin provides the diagnostic procedure for the STARLINK® Remote Engine Start (RES).
• 11027981Jan 12, 2026Other or unknown. This announcement has been created to address difficulties with software updates on Subaru Select Monitors with DST-010 interface firmware has been updated.
• 11027090Dec 12, 2025Engine, Fuel system. This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components (e.g. intake valves and / or manifold, and combustion chambers).
• 11027083Dec 8, 2025Electrical system, Engine. This Service Information Bulletin provides the Service Manual Correction to the diagnostic procedure for DTC B2A16 (Immobilizer Key Collation Diagnosis).
• 11027082Dec 8, 2025Suspension. This bulletin announces availability of new front wheel hub assemblies incorporating bearing surfaces having increased resistance to imperfections resulting from shock loads.
• 11027081Dec 8, 2025Electrical system, Engine, Fuel system. This bulletin announces the diagnostic procedures to be used when DTCs P2096 (POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1) and P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1) are detected by the Engine Control Module (ECM).
• 11027073Dec 2, 2025Electrical system. This bulletin contains illustrations of exchange components and their manufacturer as well as a description of the proper exchange procedure.
• 11025796Nov 20, 2025Other or unknown. Subaru service article locator.
• 11025790Nov 20, 2025Engine, Electrical system. This bulletin announces the diagnostic procedures to be used when DTCs P2096 (POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1) and P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1) are detected by the Engine Control Module (ECM).
• 11025789Nov 20, 2025Other or unknown. Subaru service article locator.
• 11024867Oct 29, 2025Other or unknown. This bulletin provides information on the load carrying capacity reduced label when a port-installed or retailer-installed accessory exeeds 1.5 percent of the GVWR or 100 pounds, which ever is lower.
• 11024869Oct 28, 2025Electrical system. This Service Information Bulletin outlines a systematic procedure for diagnosing parasitic draw (dark/standby current) in vehicles experiencing battery drain when the ignition is off, leading to no-start conditions or frequent jump-starts.
• 11024865Oct 28, 2025Electrical system, Transmission and drivetrain. This bulletin provides guidance when diagnosing chain slip, judder, shudder, and hesitation concerns on the TR690 model CVT transmissions used in the models listed.
• 11024864Oct 28, 2025Electrical system, Engine. This bulletin announces the diagnostic procedures to be followed when encountering cases of the Remote Engine Start (RES) system being the only non-functioning feature with telematics.
• 11024863Oct 28, 2025Other or unknown. Subaru tech tips newsletter article locator.
• 11024859Oct 28, 2025Other or unknown. Subaru tech tips newsletter article locator.
• 11024858Oct 23, 2025Electrical system. This Bulletin outlines a comprehensive update to the dark current/parasitic draw diagnosis & testing procedures.
• 11024857Oct 23, 2025Electrical system. This Bulletin provides details on a new formal testing, charging, and tracking procedure for all 12-volt batteries in new vehicle inventory.
• 11024856Oct 23, 2025Electrical system, Seats. This bulletin announces the availability of new seat ventilation blower units which have been redesigned to address some cases of a vibration-type sound emitting from the blower unit during seat ventilation operation.
• 11023536Sep 30, 2025Engine, Forward collision avoidance. In the interest of customer satisfaction Subaru of America, Inc. (SOA) is extending the New Car Limited Warranty coverage in the models listed. The extension will address instances of “phantom braking” or the EyeSight/RAB systems causing unnecessary stoppage/slowing of the vehicle.
• 11023524Sep 30, 2025Electrical system. This bulletin addresses cases when attempting to complete the STARLINK Telematics subscription process, an Error Code 202 and / or 204 may occur preventing the process from completing successfully.
• 11023508Sep 30, 2025Electrical system, Seats. This bulletin announces the availability of new seat ventilation blower units. This update is set to address some cases of a vibration-type sound emitting from the blower unit during seat ventilation operation.
• 11023509Sep 11, 2025Seat belts. This bulletin announces a design change made to the second row inner seat belt buckle assembly to address cases of the seat belt indicator warnings not turning off after the buckle is fully latched.
• 11023505Sep 5, 2025Electrical system. This bulletin announces the new procedure and Warranty Fail Code for FirstTime air conditioning (A/C) performance concerns possibly resulting from an undetected A/C refrigerant leak.
• 11023500Sep 3, 2025Electrical system. This Bulletin provides details on a new formal testing, charging, and tracking procedure for all 12-volt batteries in new vehicle inventory wjhich must be tested and reported every 30 days.
• 11023498Sep 2, 2025Transmission and drivetrain. This Bulletin announces the release of a new diagnostic assistance application for TR690 CVT-equipped vehicles.
• 11022331Aug 26, 2025Electrical system. This Bulletin provides helpful procedures and best practices to utilize when customers present with concerns relating to the operation of their Gen 2/Gen 3 Telematics system equipped Subaru.
• 11022316Aug 26, 2025Electrical system. In the interest of customer satisfaction, Subaru of America, Inc. (SOA) is extending the New Car Limited Warranty coverage for the CP1 & Gen 3.1 Head Unit used in the listed models and model years to (8) eight years / 150,000 miles to cover certain qualifying repairs to the infotainment audio system.
• 11022319Aug 21, 2025Electrical system. This bulletin contains illustrations of exchange components and their manufacturer as well as a description of the proper exchange procedure.
• 11022313Aug 14, 2025Engine. This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components (e.g. intake valves and / or manifold, and combustion chambers).
• 11022309Aug 13, 2025Electrical system. Subaru of America, Inc. will release an OTA to perform a software update to the DCM. This is a preventive OTA.
• 11022305Aug 11, 2025Engine, Electrical system, Transmission and drivetrain. Subaru Service Technical Support Newsletter special edition.
• 11022304Aug 11, 2025Body and structure. This bulletin provides information on paint codes for vehicles in the 2026 line up.
• 11022298Aug 7, 2025Seat belts. This Bulletin announces the availability of a new part Extender Belt. This is for customers who find it necessary to increase the length of their seat belt.
• 11022295Aug 7, 2025Body and structure. This bulletin provides additional examples, diagnostics tips and installation tips as helpful aids to be used when working with sunroof seals and sunroof frame assemblies on Ascent models.
• 11021266Jul 29, 2025Electrical system. In the interest of customer satisfaction Subaru of America, Inc. (SOA) is extending the New Car Limited Warranty coverage in the models listed for the selected EyeSight & Reverse Automatic Braking (RAB) components.
• 11021265Jul 29, 2025Seats, Electrical system. This bulletin announces the availability of new seat ventilation blower units.
• 11021263Jul 29, 2025Lane departure, Forward collision avoidance, Electrical system. This announcement provides information about a Subaru of America, Inc. preliminary settlement in a class action lawsuit regarding the EyeSight system in certain Subaru vehicles.
• 11021262Jul 16, 2025Electrical system. This OTA is released to address Telematic functions that may stop working after a certain amount of time from the vehicle's production.
• 11021258Jul 10, 2025Electrical system. "This bulletin announces the new procedure and Warranty Fail Code for FirstTime air conditioning (A/C) performance concerns possibly resulting from an undetected A/C refrigerant leak.
• 11021257Jul 10, 2025Electrical system. This bulletin provides information on a new reprogramming procedure (FOTA) to optimize the Harman Gen 3.1 Audio and Navigation head units (H/U) utilized in the models as listed above. Firmware-over-the-air (FOTA) is a process by which remote devices can receive updates to their operating software.
• 11021256Jul 10, 2025Electrical system. The following information addresses reprogramming file availability and a software update installation procedure to provide optimization to the new Harman Gen 3.1 Audio and Navigation head units utilized in the models as listed.
• 11019953Jun 27, 2025Other or unknown. This announcment provides information on the release of the latest software updates to the Subaru Midtronics DSS-5000 Battery Diagnostic tool.
• 11019943Jun 24, 2025Other or unknown. This announcement is to bring attention to the OTA for In-vehicle service appointment scheduler and In-vehicle message center.
• 11019932Jun 24, 2025Electrical system. This Bulletin provides additional diagnostics to follow when addressing a Telematics-related DTC B2A16.
• 11019942Jun 23, 2025Electrical system. This Service Information bulletin announces the new procedure and Warranty Fail Code for FirstTime air conditioning (A/C) performance concerns possibly resulting from an undetected A/C refrigerant leak.

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