Electropulse

From Teletraan I: The Transformers Wiki

An electropulse is an aspect of Transformer physiology and, if fading, meant they were slowly dying.

It seems comparable to a Human pulse....

[edit] Fiction

[edit] Generation 1 cartoon continuity

When Optimus Prime was heavily damaged after a Decepticon attack, his electropulse was fading rapidly and would have meant his termination had he not been repaired. Divide and Conquer

[edit] Marvel Comics continuity

There is a device showing Powermaster Optimus Prime's electropulse on his destroyed torso. Still Life!