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 26.7.3): 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 26.7.3. Release Date:• Week of June 11, 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.
M1679
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1679: AFTERMARKET EXHAUST HEADER DEBRIS. PURPOSE: Initial release. This bulletin informs dealers that Harley-Davidson has identified instances of premature engine failure due to abrasive particle wear, specifically from debris inside new aftermarket exhaust headers. Recent evaluations have identified that certain newly manufactured exhaust headers may contain residual hard particles that, if not removed prior to installation, can migrate through the engine system and cause accelerated component wear or severe mechanical damage.
M1713
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1713 (REV C): DTII UPDATE PROCEDURE FOR SOFTWARE VERSION (26.4.3). PURPOSE: Revision C. This bulletin informs dealers that an issue was discovered in the Digital Technician II (DT II) software version (26.0.2), released on November 18, 2025. The issue prevents automatic software updates to be installed on your DT II computer. A manual installation of the latest DT II software version (26.4.3) will need to be performed if current DT II software version is (26.0.2), to allow future automatic updates. If a manual update to (26.1.5) or (26.3.2) has previously been completed, DT II will automatically update to (26.4.3) and no additional action is needed.. Revision C. Updated: Purpose for Service Bulletin and Required Dealer Action. Updated to Software Version (26.4.3).
M1692
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1692: REVOLUTION MAX OIL SYSTEM SCAVENGE SCREEN. PURPOSE: Initial Release. This bulletin informs dealers that all 2026 Revolution® Max Powertains will come equipped with oil scavenge screens installed in the clutch and water pump cavities of the oil system. Oil scavenge screens prevent debris from entering the oil pump, potentially causing damage that would require additional inspection and repair to the bottom end of Revolution® Max Powertrain.
W146
Warranty Program/Extension
WARRANTY BULLETIN W146 (REV C): TIRE TREAD DEPTH GUIDE-UPDATE. PURPOSE: [Revision C. Updated: Tire Tread Depth Guide. Add tire part numbers 43100063, 43200035,43100029A, 43100033A and 43200045A.] 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.
M1555
Warranty Program/Extension
SERVICE BULLETIN M1555 (REV H): BATTERY WARRANTY GUIDELINES. PURPOSE: This bulletin informs the dealership network that Harley-Davidson has provided guidelines for battery warranty. REV H. Update section headers: AGM and Lithium-Iron Phosphate Batteries. Add graphics and callouts. Updated: Information on Battery.
PAB1165
Service Bulletin/Repair Instructions
GENUINE MOTOR PARTS AND MOTOR ACCESSORIES BULLETIN PAB1165: H-D SYN3 SAE 15W50 / SAE 50 AVAILABILITY. PURPOSE: This bulletin informs of the availability of the SYN3 New Improved Formula, a dual weight SAE 15W50 / SAE 50 Motorcycle Oil. The new formula transitions into inventory as the old SYN3 20W50 product inventory is depleted. Availability varies by SKU and region. The original SYN3 20W50 will be obsoleted when the transition is complete.
PAB1157
Service Bulletin/Repair Instructions
GENUINE MOTOR PARTS AND MOTOR ACCESSORIES BULLETIN PAB1157 (REV A): 2024 PAN AMERICA TOP CASE MOUNTING FITMENT. PURPOSE: [Revision A. Updated: Purpose for Parts and Accessories Bulletin, Summary and Thread Inspection.] Address part availability and compatibility. To inform dealers that the Top Case Mounting Kit (Part No. 53000800A) is now available and fits all 2021-2024 Pan America NON-CVO models (RA1250, RA1250S). The previous kit (Part No. 53000800) remains available and fits 2021 through 2023 Pan America (RA1250, RA1250S) vehicles.
M1558
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1558: 2021-2022 PAN AMERICA LOWER RADIATOR HOSE ROUTING. PURPOSE: This bulletin informs dealers that Harley-Davidson wants to raise awareness of proper lower radiator hose routing and installation.
M1560
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1560: REVOLUTION MAX STARTER CLUTCH GEAR UPDATE. PURPOSE: This bulletin informs dealers that Harley-Davidson wants to make aware of changes to the Revolution Max Starter Clutch Gear and aid in properly diagnosing the condition making replacement necessary.
M1559
Service Bulletin/Repair Instructions
SERVICE BULLETIN M1559: REVOLUTION MAX ECM UPDATE. PURPOSE: This bulletin informs dealers that Harley-Davidson has an Electronic Control Module (ECM) update that is available on Digital Technician II (DT II). This update is to address Diagnostic Trouble Code (DTC) P000000 setting and putting the bike into the fast idle position (4,000 rpm). The update also addresses the concern of an inadvertent tripping of P227900 for the intake air leak under certain riding conditions when no intake leak is present.