Chevy Suburban stalls. where is brain?

A Chevy Suburban doesn't have a "brain" in the same way a human does. The "brain" of a Suburban is its Powertrain Control Module (PCM), also sometimes called the Engine Control Module (ECM) or the Engine Control Unit (ECU). This is a computer that controls many aspects of the engine's operation, including fuel injection, ignition timing, and emissions.

If your Suburban is stalling, the problem could be within the PCM itself (though this is less common), or more likely, in one of the many sensors or components that the PCM relies on for information. Troubleshooting a stalling Suburban requires systematic diagnosis, and the PCM is the central point from which that diagnosis should proceed. A mechanic will use diagnostic tools to communicate with the PCM and find out what codes are stored which will help pinpoint the problem.