ETS2 Mac controller rumble

A tiny Euro Truck Simulator 2 plugin for macOS that makes the game's own controller rumble work with gamepads that Steam Input reports as "Unknown", such as the 8BitDo Pro 3 in D mode over Bluetooth.

Without it, such a controller works fine for driving but never vibrates. With it, you get the game's normal rumble (road surface, braking, collisions…), delivered by Steam exactly as for an Xbox or PlayStation controller.

The problem

ETS2 sends vibration only to controller types that it has a motor mapping for. Its steam_controller_vibration definitions cover Steam Input types 1–5, 10 and 13 (Steam Controller, Xbox, generic gamepad, PlayStation, …). A controller that Steam Input reports as type 0, Unknown, gets no vibration commands at all. Steam itself is perfectly able to rumble it; the game just never asks.

How the plugin fixes it

The plugin is loaded by the game through the SCS Telemetry SDK (it doesn't use any telemetry data; that's only how it gets loaded). Inside the game, it patches four entries of the game's ISteamInput (SteamInput006) interface:

• GetInputTypeForHandle: an Unknown controller is reported as a Generic Gamepad (type 4), so the game uses its standard gamepad vibration mapping. Steam then delivers the rumble itself.
• GetConnectedControllers: the game sets controllers up about 3 seconds after launch, but plugins only load at about 11 seconds. The plugin answers the game's next 2 polls (about 2 seconds) with "no controllers", so the game sets the controller up again, this time as a gamepad.
• TriggerVibration / TriggerVibrationExtended: passed through unchanged and counted, for the log.

Before patching, the plugin checks that every slot it replaces points into Steam's own client library. If the layout is not what it expects (for example after a game or Steam update), it logs a warning and leaves everything as it was. The original interface is restored when the game unloads the plugin.

Tested with

Game	Euro Truck Simulator 2 1.61.1.9s (Steam, macOS, Vulkan renderer)
macOS	27.0.1, Apple M3 Pro (the game runs under Rosetta)
Controller	8BitDo Pro 3 in D mode, Bluetooth (2dc8:6009)

Other controllers that Steam Input reports as Unknown should benefit in the same way, but I haven't tested any. Controllers that Steam already recognises (Xbox, PlayStation, Switch Pro, …) don't need this plugin. American Truck Simulator uses the same engine and might work too; it is untested.

Install

1. Get the plugin

Download it from the latest release. The simplest way is in Terminal, which saves it to your Downloads folder:

curl -L -o ~/Downloads/ets2_steam_input_fix.dylib \
  https://github.com/rshrj/ets2-mac-controller-rumble/releases/latest/download/ets2_steam_input_fix.dylib

If you download it with a browser instead, macOS marks the file as quarantined, and the game won't be able to load it (macOS shows "Apple could not verify … is free of malware"). The plugin isn't signed with an Apple Developer ID, so clear that mark once:

xattr -d com.apple.quarantine ~/Downloads/ets2_steam_input_fix.dylib

Or build it yourself. You need the Xcode Command Line Tools (xcode-select --install):

git clone https://github.com/rshrj/ets2-mac-controller-rumble.git
cd ets2-mac-controller-rumble
make

2. Copy it into the game

Put ets2_steam_input_fix.dylib into the game's plugins folder:

1. In Steam, right-click Euro Truck Simulator 2 → Manage → Browse local files.
2. Right-click Euro Truck Simulator 2.app → Show Package Contents, then open Contents/MacOS.
3. Create a folder called plugins there if it doesn't exist, and put ets2_steam_input_fix.dylib in it.

macOS normally blocks Terminal from writing inside other apps, which is why Finder is the easy way. If you built it yourself and have given your terminal the App Management permission (System Settings → Privacy & Security), make install does the same copy.

Make sure vibration is enabled both in the game's controller options and in Steam's settings for the controller.

Check that it works

Start the game. About 11 seconds after launch the controller shows as missing in the game's controller settings for 2–3 seconds, then comes back. That's the plugin making the game set it up again.

The game log (~/Library/Application Support/Euro Truck Simulator 2/game.log.txt) should contain:

[steam-input-fix] installed (redetect_polls=2)
[steam] Initializing device '@@steam_controller@@ …' … hw: Generic Input (4)

and, after you quit the game, a summary like:

[steam-input-fix] type queries=3 (overridden 3), vibration calls=46502, hidden polls=2

A non-zero number of vibration calls means the game is sending rumble to your controller.

Uninstall

Delete ets2_steam_input_fix.dylib from the game's plugins folder (or run make uninstall).

Limitations

• macOS only. The plugin is built for x86_64, like the macOS game. The same idea could work on Windows or Linux but would need a different build, and I haven't tried it.
• Depends on the game's Steamworks version. The plugin relies on the SteamInput006 interface and its method order. If a future game update changes that, the plugin logs a warning and does nothing.
• The controller drops out for 2–3 seconds about 11 seconds after launch.

Other ETS2-on-Mac notes

Two things I found while setting this up, in case they save someone time:

• HDR breaks the Steam overlay. With HDR on, ETS2 by default uses a 10-bit BT.2100 PQ swapchain, which the Steam overlay (Shift+Tab, notifications, the in-game store) draws as psychedelic garbage, with blacks turning bright blue. Adding the launch option -color_space scrgb makes the game use a 16-bit floating-point scRGB swapchain instead; HDR still works and the overlay draws correctly. (-color_mode only accepts sdr; other values are ignored.)
• -mvk-arg-buffers made things worse on an M3 Pro: random frame freezes. The game disables Metal argument buffers on x86_64 by default for a reason.

My full launch options are -rdevice vk -color_space scrgb.

Experimental: telemetry-based rumble

experimental/ has an earlier, larger approach: a plugin that streams truck telemetry to a native helper, which generates its own rumble effects from suspension, road surface and collisions, and can record and replay drives for tuning. It is unfinished and not needed for the game's own rumble; see its README.

Credits and licence

• scs_sdk/ contains the SCS Telemetry SDK headers, © SCS Software, MIT licence (scs_sdk/sdk_license.txt).
• This project is not affiliated with SCS Software, Valve or 8BitDo.

Released under the MIT licence.