We consider marked empirical processes indexed by a randomly projected functional covariate to construct goodness-of-fit tests for the functional linear model with scalar response. The test statistics are built from continuous functionals over the projected process, resulting in computationally efficient tests that exhibit root-n convergence rates and circumvent the curse of dimensionality. The weak convergence of the empirical process is obtained conditionally on a random direction, whilst the almost surely equivalence between the testing for significance expressed on the original and on the projected functional covariate is proved. The computation of the test in practice involves calibration by wild bootstrap resampling and the combination of several p-values, arising from different projections, by means of the false discovery rate method. The finite sample properties of the tests are illustrated in a simulation study for a variety of linear models, underlying processes, and alternatives. The software provided implements the tests and allows the replication of simulations and data applications.The term "goodness-of-fit" was introduced at the beginning of the twentieth century by Karl Pearson, and, since then, there have been an enormous amount of papers devoted to this topic: first, concentrated on fitting a model for one distribution function, and, later, especially after the papers of Bickel and Rosenblatt (1973) and Durbin (1973), on more general models related with the regression function. Considering a regression model with random design Y = m(X) + ε, the goal is to test the goodness-of-fit of a class of parametric regression functions M Θ := {m θ : θ ∈ Θ ⊂ R q } to the data. This is the testing ofis the regression function of Y over X, and ε is a random error centred such that E [ε|X] = 0. The literature of goodness-of-fit tests for the regression function is vast, and we refer to González-Manteiga and Crujeiras (2013) for an updated review of the topic.Following the ideas on smoothing for testing the density function (Bickel and Rosenblatt, 1973), the pilot estimators usually considered for m were nonparametric, for example, the Nadaraya-Watson estimator (Nadaraya (1964), Watson (1964K (x − X j )/h , where K is a kernel function and h is a bandwidth parameter. Using these kinds of pilot estimators, statistical tests were given by T n = d m, mθ , with d