QPKING M4 Motorcycle Scan Tool for Harley-Davidson - 4P/6P Compatible, Full-System Diagnostics & ABS Bleeding (Up to 2023)

The QPKING M4 is a compact, Harley-focused diagnostic scanner that reads/clears codes, displays live data, runs service functions and performs supported ABS bleeding on compatible Harley-Davidson models up to 2023.

The M4 is built specifically for Harley-Davidson motorcycles with either the round 4-pin or 6-pin diagnostic port and offers deeper motorcycle-focused coverage than a generic OBD2 reader. It connects to the bike’s 12 V power and provides a 2.8-inch multilingual screen for on-bike troubleshooting, system checks and basic adjustments. Firmware updates are applied via an SD card formatted as FAT32 so you can keep the tool current without removing power.

How do I know if the M4 works with my Harley-Davidson?

Compatibility depends on the bike’s diagnostic connector and ECU support; confirm your motorcycle has the round 4-pin or 6-pin port and check model-year coverage. The M4 supports many Harley systems but functionality can vary by year and specific ECU.

• Fits Harley models with round 4P or 6P diagnostic ports
• Verify model year and ECU support before purchase
• ABS bleeding supported on compatible models through 2023 only

What diagnostic functions can the M4 perform on a Harley?

The M4 offers full-system reads and clears for supported fault codes, live data streams, ECU information, and a range of service resets and active tests. On compatible motorcycles you can run adjustments and service procedures that help with routine maintenance and troubleshooting.

• Read and clear supported diagnostic trouble codes
• View live sensor data and ECU details on the 2.8" display
• Execute supported service resets and active tests

What are the cables and their differences?

The M4 ships with two distinct cables to cover motorcycle-specific functions and basic OBD2 operations. Use the Harley 4P/6P cable for the bike’s full feature set; the OBD2 16-pin cable provides basic engine code reading and live data for cars only.

• Harley 4P/6P cable: full diagnostics, resets, active tests, and ABS bleeding (when supported)
• OBD2 16P cable: basic car engine codes, clearing and live data only
• Always connect to the correct port for the intended functions

How do I operate and update the M4?

The device runs from your motorcycle’s 12 V supply and requires no internal battery; its 2.8-inch screen supports 17 languages for on-bike use. Updates are applied with the official update package placed on a FAT32 SD card while the tool remains powered.

• No internal battery — plug into the bike’s 12 V system to operate
• 2.8" display with selectable language options for ease of use
• Update firmware via FAT32 SD card without disconnecting power

Who is this for: The QPKING M4 is aimed at Harley-Davidson owners, home mechanics and professional technicians who need a dedicated motorcycle diagnostic tool that goes beyond basic OBD2 scanning. If you service Harley motorcycles with round 4-pin or 6-pin diagnostic ports and want live data, code management, service resets and supported active tests — including ABS bleeding on eligible models through 2023 — the M4 is built to make diagnostics faster and more precise. It is not intended as a universal solution for non-Harley bikes that lack the required connector or for 2024+ Harley ABS bleeding support.