The Vehicons always confused me. Did they have sparks? Or were they high-level drones capable of some autonomy but were still mostly really stupid? Also, where did they all come from? It seems so odd that they are all the same whereas all the other robots are individuals. It's always confused me.
shareFrom what I gathered, during most of the show's development they were meant to be mere drones (which is why, for example, they were designed without expressive faces), but in the end, they became genuine "living" Transformers that form a giant legion. They at times act individually, Optimus once berated Ratchet for torturing a miner-class Vehicon, and the Spark Extractor clearly worked on them, so yeah, they have Sparks.
shareSteve had a spark.
During the defense of the Omega Lock the Spark Extractor (http://tfwiki.net/wiki/Spark_extractor) is used by Smokescreen to kill a large group of Vehicons suggesting that they do indeed have sparks.
It is never really explained whether or not they are cloned, or how they are birthed; if there are a finite number of them or if they are manufactured in some way. Given that Shockwave was able to use CNA to clone the extinct predacon species, it's possible that the Vehicons are also genetic clones grown to do menial labour and serve as cannon fodder which would explain why they all seem to suffer from the same deficiencies.