ECM's w/ Integral Auto Tune System / '01-'20

The ThunderMax ECM with Integral Auto Tune replaces the factory ECM on '01-'20 Harleys and self-tunes continuously using wide band oxygen sensors.

A closed loop system is the difference between a tune and a snapshot. ThunderMax reads air fuel ratio through wide band O2 sensors and adjusts continuously across all riding conditions, which means the tune follows altitude, temperature and how you actually ride rather than being fixed to one afternoon on a dyno. No dyno session is required at all.

How the ThunderMax System Works

The ECM mounts in place of the factory unit and plugs into the existing harness. Installation is a sequence rather than a project: replace the ECM, fit the new O2 sensors and harness, load the correct map, ride. Hundreds of maps are available to download based on model, engine size, exhaust, air cleaner, pistons and cams, so the starting point is close before auto-tune refines it.

TMax software allows live monitoring, recording and examination of diagnostic codes and datalogs, including number of starts, engine temperature and rpm operation. Front and rear cylinder AFR maps, ignition timing maps and startup maps are all adjustable. The rider can set idle speed, rev limit and speedometer calibration. Turbo, nitrous and supercharger applications are supported. New maps, software, firmware updates, map analysis and tech support are available online at no charge.

ThunderMax Integral Auto Tune Specifications

• Fitments A through I covering '01-'20 Touring, Softail, Dyna, Sportster, Trike and XR1200
• Includes ECM with Auto-Tune module, plug-in harness, two wide band sensors, TMax software and USB cable
• Closed loop continuous self adjustment of air fuel ratio
• Adjustable front and rear cylinder AFR, ignition timing and startup maps
• Rider adjustable idle speed, rev limit and speedometer calibration
• Works with popular exhaust systems and high performance camshafts
• Supports turbo, nitrous and supercharger applications
• No dyno tuning required
• Made in the USA

Important Fitment Notes

Option A is not for use on models with traction control. Options B, C, E and F require an exhaust system with 18mm sensor bungs, or headpipes modified to accept 18mm sensors. Options A and D are not interchangeable or upgradable from part numbers 1020-2118 or 1020-2526.

Because of possible clearance issues, some aftermarket exhaust systems may require modification or relocation of their O2 sensor port bungs.

⚠️ VERIFY which lettered option matches your model and year, and confirm your exhaust sensor bung size before ordering.