Signal Flare has taken a different tactic to protecting Earth from the Decepticons. Eschewing combat, he prefers to hide among the humans and secretly help build their structures to withstand damage from Decepticon weaponry, rather than the mission of fighting that big green, fire-snortin' lizard which might be implied by his alt mode. He also remains vigilant in watching out for any Decepticon activity on Earth, quickly transmitting details to the Autobot high command.
He's found a prime staging ground at the Wash & Roll, an automobile service station and car wash near the Witwickys' home. It's from here that he keeps his fellow Autobots clean and properly maintained.