Public distribution home for the Gear Control Unit (GCU) firmware that runs the Rush SR's pneumatic sequential paddle shifter. This repo carries the downloadable firmware bundles, the release notes, and the flashing instructions.
It is a distribution repo: it holds the ready-to-flash firmware bundles, the release notes, and the flashing guide. The firmware source code lives in a separate, private repository.
Rush has shipped two GCU generations. Pick the right one before you flash.
| Active GCU | Legacy GCU | |
|---|---|---|
| Fitted to | Newer builds (Gen2, drive-by-wire) | Earlier builds (Gen1, throttle cable) |
| Hardware | Small flat black box, one multicolor LED | Large grey box, two metal connectors, red/yellow/green LEDs |
| Firmware | 5.x (.bin files) |
3.x (.hex files) |
| Flashing | USB-C on the piggyback harness (dealer-installed if absent) | USB-B on the unit |
Not sure which you have? Gen1 cars have a throttle cable at the pedal box; Gen2 cars have an accelerator pedal sensor (no cable). The Active GCU also reports firmware 5.x on connect — the flasher prints the version automatically.
Grab the latest bundle from Releases. Each release zip contains the firmware for the relevant unit(s) plus the GCU Flasher app:
- Active GCU (5.x) —
release_CAN_feather-X.X.X.bin/release_KLine_feather-X.X.X.bin - Legacy GCU (3.x) —
release_CAN-X.X.X.hex/release_KLine-X.X.X.hex
See docs/flashing.md for the full step-by-step — the USB cable, the GCU Flasher app (macOS + Windows), picking the right firmware file, and the built-in serial console for diagnostics.
CHANGELOG.md is the source of truth for what changed in each release. Older versions (3.0.3 and earlier) are not published here — contact Rush Auto Works.
Maintained by Rush Auto Works. The owner's manual GCU pages mirror this repo's releases.