Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
M1490
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1490 (V 26.8.3): DIGITAL TECHNICIAN II - UPDATES AND RELEASE NOTES. PURPOSE: Revision. This bulletin informs dealers that Harley-Davidson has made a software update to Digital Technician II (DT II). DIGITAL TECHNICIAN II (PART NUMBER: HD-48650). Version Version 26.8.3, Release Date: Week of July 24, 2026. NOTE: Software version (26.4.3) will need to be manually installed only if current software version of DT II is (26.0.2). After (26.4.3) is manually installed, automatic updates will bring DT II to the latest software version. Refer to bulletin M1713 for instructions. New Features - Harley-Davidson: 2023-2024 Touring: Updated Electronic Control Module (ECM) calibration offerings. LiveWire: S2DM/MH/AP: Calibration bundle 10.2.28: Telematic Control Unit (TCU) reflash updates. Change: Vehicle Setup: Body Control Module (BCM) – Tire Pressure Monitoring System (TPMS) Replacement: Correct issue where tire size selections were not available. System Info – Auxiliary Load Controller (ALC): Added Bike configuration field. Data Items – Trike ECM: Improved display of Gear Position when in reverse. Amp – Added support for (Part No. 76001619).
L1026
Service Bulletin/Repair Instructions
SERVICE BULLETIN L1026: TECH TIP 002 - S2 12 VOLT BATTERY BEST PRACTICES. PURPOSE: Initial Release. This bulletin informs dealers of best practices for diagnosing a LiveWire S2 vehicle that presents a depleted or fully-discharged 12 V battery and making sure contributing issues are identified. Use this bulletin’s troubleshooting guidance to help identify contributing issues affecting 12 V battery health. A depleted or fully discharged 12v battery may be the result of other systems or components affecting 12 V battery health. Or it may be the result of expected behavior relating to certain conditions the 12 V battery was exposed.
L1025
Service Campaign
SERVICE BULLETIN L1025: PRODUCT PROGRAM 1902 S2 ABS/EHCU MODULE CORRECTION. PURPOSE: Initial Release. This bulletin informs dealers that the Anti-lock Braking System / Electro -Hydraulic Control Unit (ABS EHCU) module on some S2 Del Mar and Mulholland vehicles have a software configuration that prevents them from being unlocked. This prevents the ability to perform an ABS service bleed and software updates. It does not affect the operation of Anti-lock Braking System (ABS). The update is applied by Digital Technician II (DT II) and will apply a seed and key to the Electro Hydraulic Control Unit (EHCU), which enables it to be unlocked via DT II or Firmware Over The Air (FOTA) update. The affected vehicles will also require an EHCU reflash following the update.
L1017
Service Bulletin/Repair Instructions
SERVICE BULLETIN L1017: 2024 S2 MULHOLLAND VSC SOFTWARE UPDATE. PURPOSE: This bulletin informs dealers that in the Digital Technician II (DT II) release version (24.12.4), it will include a Vehicle Supervisory Controller (VSC) application software update version for the 2024 S2 Mulholland, that will appear to be a lower numbered version than the previous release. This was done to unify the S2 VSC software versions between Del Mar and Mulholland. The Del Mar is unaffected by this change. • The new VSC software is (13.5.5) • The prior release is (13.5.24). Due to this version number, DT II will not highlight this version in red as being an available update.
L1019
Service Campaign
PRODUCT PROGRAM COMMUNICATION L1019 DEALER LETTER: PRODUCT PROGRAM 1901 S2 TCU REPLACEMENT. PURPOSE: DEALER LETTER COMMUNICATING IMPORTANT PRODUCT PROGRAM INFORMATION, Product Program 1901, MY24 LiveWire® S2 TCU Software in support of SERVICE BULLETIN L1019: PRODUCT PROGRAM 1901 S2 TCU REPLACEMENT.
L1020
Service Bulletin/Repair Instructions
SERVICE BULLETIN L1020: S2 COOLING SYSTEM FILL AND BLEED TIPS. PURPOSE: Initial Release. This bulletin provides dealers with best practices for filling and bleeding the cooling system on S2 models after component replacement. This can help prevent customer vehicle returns due to unpurged air in the cooling system. The most common symptom of this is the turtle icon illuminating on the instrument module after only a few minutes of riding.
M1555
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1555 (REV G): BATTERY WARRANTY GUIDELINES. PURPOSE: [Revision G: Updated: Information on Battery. Update section headers: AGM and Lithium-Ion Batteries.] This bulletin informs the dealership network that Harley-Davidson has provided guidelines for battery warranty.
L1016
Service Bulletin/Repair Instructions
SERVICE BULLETIN L1016 (REV C): S2 TCU UPDATE PROCEDURE FOR V4.0.6 AND EARLIER. PURPOSE: Revision C. This bulletin informs that this procedure should be followed when troubleshooting or updating Telematic Control Unit (TCU) software when version 4.0.6 or earlier is installed in the module. This procedure improves the likelihood of gaining and maintaining TCU connectivity, and reduces the need to replace the module. Revision C: Updated: Supplemental Procedure Video. Add video link.
W146
Warranty Program/Extension
WARRANTY BULLETIN W146 (REV B): TIRE TREAD DEPTH GUIDE-UPDATE. PURPOSE: [Revision B. Updated: Tire Tread Depth Guide. Add tire part numbers 43200063 and 43200038A.] To provide tire tread depth specifications for the dealership network to consult when filling warranty claims on used tires. Please see the Warranty Manual of your region for tire policy guidelines. Updated: Tire Tread Guide. Add tire part number 43100038B. Update tire tread depth, adjustment and reimbursement.
L1014
Service Bulletin/Repair Instructions
SERVICE BULLETIN L1014: S2 INSTRUMENT MODULE DISPLAYING WRENCH ICON. PURPOSE: This bulletin informs dealers that some S2 Del Mar and Mulholland vehicles may incorrectly have the wrench icon (maintenance required) illuminated at the time of Predelivery Inspection (PDI). The wrench icon is a time-based service reminder and should only first come on two years after the date of manufacture. The Body Control Module (BCM) controls the display of this icon and may have its internal clock altered incorrectly by the Telematic Control Unit (TCU). NOTE: Correction of Communication Date in portal transaction ID: 24MC11001286 due to new portal interface use.