ULC Events

ULC provides client events that other FiveM resources can use to control configured vehicle extras or react to lighting state changes.

These events are client-side. Call them with TriggerEvent and listen for them with AddEventHandler. Do not use TriggerServerEvent for the events on this page.

Set an extra or stage

Use ulc:SetStage to enable, disable, or toggle an extra on the vehicle that the local player is currently using with ULC.

TriggerEvent(
    "ulc:SetStage",
    extra,
    action,
    playSound,
    extraOnly,
    repair,
    forceChange,
    forceUi
)

Arguments

Argument	Type	Description
`extra`	number	The vehicle extra ID to control.
`action`	number	`0` enables, `1` disables, and `2` toggles the extra.
`playSound`	boolean	Plays ULC's enable or disable beep when the extra belongs to a configured button.
`extraOnly`	boolean	When `true`, changes only this extra. When `false`, ULC also processes its configured linked, opposite, and off extras.
`repair`	boolean	Uses ULC's repair behavior while changing the extra. The change is rejected if the vehicle is damaged or a door is open. Usually `false`.
`forceChange`	boolean	Processes the action even if the extra is already in the requested state. This is useful when linked or off extras must still be processed. Usually `false`.
`forceUi`	boolean	Forces the configured ULC button display to update when `extraOnly` is `true`. Usually `false`.

The player must be inside a vehicle recognized by ULC. If extra belongs to a configured ULC button, using extraOnly = false preserves that button's normal stage and linked-extra behavior.

Examples

Enable extra 12 and process its configured linked, opposite, and off extras:

TriggerEvent("ulc:SetStage", 12, 0, true, false, false, false, false)

Disable only extra 12 without playing a sound:

TriggerEvent("ulc:SetStage", 12, 1, false, true, false, false, false)

Toggle extra 12 and update its ULC button:

TriggerEvent("ulc:SetStage", 12, 2, true, false, false, false, true)

Listen for ULC state changes

External client resources can listen for the following events. These events are notifications from ULC; use them to react to state changes rather than to control those states.

Emergency lights

ulc:lightsOn is emitted when the local vehicle's emergency lights turn on. ulc:lightsOff is emitted when they turn off. Neither event has arguments.

AddEventHandler("ulc:lightsOn", function()
    print("Emergency lights turned on")
end)
 
AddEventHandler("ulc:lightsOff", function()
    print("Emergency lights turned off")
end)

Park and drive states

ulc:vehPark is emitted when ULC changes to its parked-lighting state. ulc:vehDrive is emitted when ULC changes back to its driving-lighting state. Neither event has arguments.

AddEventHandler("ulc:vehPark", function()
    print("ULC entered the parked state")
end)
 
AddEventHandler("ulc:vehDrive", function()
    print("ULC entered the driving state")
end)

Turn indicators

ulc:indicatorStateChanged is emitted when the local vehicle's turn-indicator state changes.

AddEventHandler("ulc:indicatorStateChanged", function(newState, oldState)
    print(("Indicator state changed from %s to %s"):format(oldState, newState))
end)

Argument	Type	Description
`newState`	number	The current indicator state: `0` off, `1` left, `2` right, or `3` hazards.
`oldState`	number	The indicator state before the change, using the same values.

The state-change events describe the local player's current vehicle. If an integration needs a vehicle handle, it can retrieve it when the event runs:

AddEventHandler("ulc:lightsOn", function()
    local vehicle = GetVehiclePedIsIn(PlayerPedId(), false)
    if vehicle == 0 then return end
 
    -- Use the vehicle in your integration.
end)

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