SERVICE BULLETIN
M1666

2025-01-27

M1666: SKYLINE OS VERSION 4125D SOFTWARE UPDATE
All other updates to customer-owned motorcycles which are
not performed to address an issue in the “Fixes” section and/or
are not performed to address parts found under normal use to
be defective in factory materials or workmanship, are not eligible
for a Warranty claim. Vehicles outside of the Limited Warranty
period are not eligible to have this software update covered
under warranty.

Reason for Revision
Refer to Table 1.
Table 1. Document History
Date
Rev
Revision (Rev) Description
2025-01-27 - Initial release

Pre-Delivery Updates

Purpose for Service Bulletin
NOTE
Service Bulletin M1666 supersedes M1635. Repairs made
to vehicles after January 27th, 2025 following M1635 will
not be accepted through warranty. Warranty claims on
repairs made prior to January 27th, 2025 will be accepted
following standard claim submission policy and process.
This bulletin informs dealers that there is a Skyline OS software
update for the 2023 and 2024 Touring vehicles equipped with
an Infotainment Control Unit (IFCU). This software update
(260004125D) will bring 2023 and 2024 IFCU equipped vehicles
to the most up to date software version. This update should be
performed on bikes exhibiting concerns covered in the release
notes to be covered under warranty.

All new and unsold units in your inventory should be updated
to this software prior to being sold and delivered.

Release Notes
Fixes:
• Software update process operation.
• Battery drain potentially caused by IFCU response to
customer interaction with the motorcycle when it should be
in an off-power state
• Subwoofer Gain adjustment functionality
• Intermittent CarPlay connection and interaction
• Intermittent mixed display High Contrast/Dark Mode

The software update will add features and address a series of
bugs within 2023 and 2024 vehicles equipped with the Skyline
OS.

• Intermittent access and display of main menu and widgets

This update can be applied to all current software versions:
240001467D, 240002100D, 240002111D and 240002237D.

• Intermittent loss of audio due during a low battery voltage
engine start

This is a multi-step software update that also contains the latest
Amplifier software version (1.5.4.0). This update addresses
potential lock ups and other update process issues, but the
software must be fully installed for the changes to take effect.
Follow the provided support information to address any issues
that may be encountered during the update.

• Navigation not enabling correctly after purchase of
embedded navigation

This software update is available on Service Information Portal
(SIP) where it can be downloaded and installed by the customer
and dealer at their convenience.

Enhancements:

Fixes vs. Enhancements - What is Covered
Under Warranty
For software updates completed to address a customer concern
listed in the “Fixes” section on motorcycles within the Limited
Warranty period, please file a Warranty claim for completing
the work and note the customer’s concern in the comments
section of the claim.

• Intermittent audio playback
announcement or prompt

interruption

after

an

• Loss of audio or menu not loading after ignition cycle
• Global Positioning System (GPS) location not updating after
quick ignition cycle

• Trip A/B widget accuracy
• Intermittent incorrect displaying of Diagnostic Trouble Code
(DTC) U148983
• Original Equipment (OE) audio configuration sound

Added Features:
• Map Zoom in/out with Left Hand Control Module (LHCM)
up/down buttons on Directional Pad
• Parts and Accessories (P&A) Audio content (added speaker
Stage levels and Subwoofer auto detect)

NOTE
In the interest of preserving customer safety and satisfaction, always check for outstanding recalls whenever any motorcycle is brought into your dealership for either maintenance or service.
ROUTING

INITIAL HERE

SERVICE
MANAGER

SALES MANAGER PARTS MANAGER

WARRANTY
PROCESS
MANAGER

LEAD TECHNICIAN TECHNICIAN NO. 1 TECHNICIAN NO. 2 TECHNICIAN NO. 3 RETURN THIS TO

• Enables Over The Air (OTA) updates

Markets Affected

Required Dealer Action

All markets affected.

Part Numbers

Table 2. Required Dealer Action
Category

Description

1

Must Perform Repair

2

Repair If Presenting Symptom

3

Feature PackCustomer/Dealer Paid

4

Informational Purposes Only

Required

NOTE
If software in the IFCU and amplifier are the latest software, no
update is needed.
Repeating updates on vehicles that have already been done,
will not be paid.
Check Amp software version on the IFCU, use the following
menu path: SETTINGS > SYSTEM > SYSTEM INFO >
PRODUCT INFORMATION
NOTE
When doing multiple vehicles, notice that additional folders are
being added to the Universal Serial Bus (USB) drives by the
IFCU. This is normal and those empty folders do not affect the
update process from vehicle to vehicle.

Refer to Table 3.
Table 3. Part Numbers
Model Year
2023
2023
2023
2024
2024
2024

Part No.
70901090
70901092
70901093
70901090A
70901092A
70901093A

1.

Remove all older software updates from previously used
USB drives. It is recommended to reformat those drives to
the proper exFAT format to ensure the correct format and
that all files are removed from the drive. Follow USB Drive
Best Practices to ensure correct files and drive setup. Refer
to: Infotainment Control Unit (IFCU) Support Resources.

2.

Download software files for USB 1 and USB 2.

3.

Unzip files from downloads for USB1 and USB2 to the root
directory of the respective files.

4.

These drives will then be used to update vehicles going
forward.

Market
DOM
HDI
ROW
DOM
HDI
ROW

Credit Procedure
NOTE
For vehicles within factory warranty, submit a warranty claim
per Table 4.
Table 4. Skyline OS Version 4125D Software Update
ITEM
Claim Type
Problem Part Number
Quantity
(1)

UPDATE PREPARATION

Item Description
IFCU
IFCU
IFCU
IFCU
IFCU
IFCU

Primary Labor Code
Labor Time
Customer Concern Code
Condition Code

DATA
PRDMC/DEM PDI/Standard claim
Refer to Table 3.
Leave Blank
1759
1 hours
9203
1759

(1) Download may be required

UPDATE SOFTWARE
For step by step instructions on the software update, Refer to:
Infotainment Control Unit (IFCU) Support Resources.

CONFIRM UPDATE
Once both USBs have been installed and completed, navigate
to the IFCU menu to confirm IFCU software version is reading
260004125D and Amplifier is reading 1.5.4.0

Vehicles Affected
2023: CVO Street Glide (FLHXSE), CVO Road Glide
(FLTRXSE)
2024: Street Glide (FLHX), Road Glide (FLTRX), CVO Street
Glide (FLHXSE), CVO Road Glide (FLTRXSE), CVO Road
Glide ST (FLTRXSTSE)

2/2

M1666