A computer includes a processor and a memory, the memory storing instructions executable by the processor to collect first sensor data from a time-of-flight sensor, collect second sensor data from one or more sensors, generate a virtual map of at least one of a light reflectivity or a depth from the time-of-flight sensor from the collected first sensor data and the collected second sensor data, determine a difference between the light reflectivity or the depth of each pixel of the first sensor data from the light reflectivity or the depth of each corresponding pixel of the virtual map, determine an occlusion of the time-of-flight sensor as a number of pixels having respective differences of the light reflectivity or the depth exceeding an occlusion threshold, and actuate a component to clean the time-of-flight sensor when the occlusion exceeds an occlusion threshold.