ThunderMax ECM with Auto-Tune is a replacement for the stock Harley-Davidson engine control module that tunes the fuelling to your motorcycle by itself. Fitted an aftermarket exhaust, a high-flow air filter or a completely different engine — ThunderMax adapts automatically.
The module works in closed loop with two wideband O2 sensors: it constantly monitors the mixture and corrects it in all riding modes. Just select and load a suitable map from the ThunderMax library, and Auto-Tune does the rest — no trips to the dyno.
The TMax software lets you adjust idle speed, rev limit, speedometer calibration, ignition and fuel maps for each cylinder, and view trouble codes and engine logs. The result is sharper throttle response, better exhaust sound and smoother engine running. Installation is simple: the module fits in place of the stock one and plugs into the stock wiring.
ThunderMax ECM engine control module kit with integrated Auto-Tune module for Harley-Davidson motorcycles.
| Type | Model fitment | Part number | Note |
|---|---|---|---|
| Engine control module (ECM) | For FLHX/ | 1020-4289 | Fits models with VVT and non-VVT engines. |
| Engine control module (ECM) | For FLHTK/ | Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For FLHT/ | Not interchangeable with 1020-2118 and 1020-2526, cannot be upgraded from them. Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For FLHT/ | ||
| Engine control module (ECM) | For FLHT/ | Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For Softail 2021–2024. | Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For Softail 2018–2020. | Not interchangeable with 1020-2118 and 1020-2526, cannot be upgraded from them. Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For FXS/ | Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For FXS/ | Requires an exhaust with 18 mm sensor ports, or the pipes must be modified for 18 mm sensors. | |
| Engine control module (ECM) | For FXS/ | ||
| Engine control module (ECM) | For FXST/ | ||
| Engine control module (ECM) | For FXCW/ | Mini USB adapter included. | |
| Spare part | Replacement 18 mm oxygen sensor (each). |
