Each Transformer has a unique identifying energy signature. That energy signature can usually be used to identify someone's faction. Certain substances or devices can mask a Transformer's energy signature from detection. The type of energy is unknown, possibly infrared.
All the Maximals' energy signatures were undetectable by the Vehicon drones when the Maximals were in beast mode. The signatures became detectable again whenever the Maximals were in robot mode.
Optimus was unable to detect Elita-1's energy signature when she was mutated into a half-organic being. This led him and Sentinel to believe that she was killed, causing a falling out between the pair.
Prime was able to detect Prowl's energy signature when the latter was consumed by a nano-machine-enhanced bug. He noted that it was weak, indicating a connection between the signature and the subject's health.
- ↑ To test the Predacon Autoguns, Megatron programmed a target box to emit the Maximals' energy signatures.
- ↑ In the Beast Wars episode "Coming of the Fuzors", the Predacon security system identifies Dinobot's "Maximal infrared signature." It's unclear whether this is the same as an energy signature or the computer was simply programmed to recognize the infrared "fingerprint" of every known Maximal.