[Correlli]

Example:

pawn Код:

if(IsPlayerInAnyVehicle(playerid))
{
  new
      Float:vehicleHealth, vehicleID;
  vehicleID = GetPlayerVehicleID(playerid);
  GetVehicleHealth(vehicleID, vehicleHealth);
  if(vehicleHealth <= 500.0) SetVehicleHealth(vehicleID, 1000.0);
}

Note that vehicle's maximum health is 1000, this code will fix vehicle if it's health is 500.0 or below.
If you would like to repair vehicle's visual damage, then use RepairVehicle(...) function.