This paper presents an integrated fault detection (FD) and fault-tolerant control (FTC) architecture for spatially distributed processes described by quasi-linear parabolic partial differential equations (PDEs) with control constraints and control actuator faults. Under full state feedback conditions, the architecture integrates model-based fault detection, spatially distributed feedback, and supervisory control to orchestrate switching between different actuator configurations in the event of faults. The various components are designed on the basis of appropriate reduced-order models that capture the dominant dynamics of the distributed process. The fault detection filter replicates the dynamics of the fault-free reduced-order model and uses its behavioral discrepancy from that of the actual system as a residual for fault detection. Owing to the inherent approximation errors in the reduced-order model, appropriate fault detection and control reconfiguration criteria are derived for the implementation of the FTC architecture on the distributed system to prevent false alarms. The criteria is expressed in terms of residual thresholds that capture the closeness of solutions between the fault-free reduced and full-order models. A singular perturbations formulation is used to link these thresholds with the separation between the slow and fast eigenvalues of the spatial differential operator necessary for closed-loop stability. Under output feedback conditions, an appropriate state estimation scheme is incorporated into the control architecture, and the effects of estimation errors are accounted for in the design of the feedback controller, the fault detection filter, and the control reconfiguration logic. The proposed approach is successfully applied to the problem of constrained, actuator fault-tolerant stabilization of an unstable steady state of a representative diffusion-reaction process.