Engine Control Module/Powertrain Control Module (ECM/PCM)
WARNING: This page is about a different car, the 2008 Isuzu Ascender, 2008 GMC Envoy, and 2008 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The ECM/PCM contains the remainder of the logic of the immobilizer system. If a serial data message containing a valid fuel enable password is received from the BCM, the ECM/PCM will continue to allow the fuel injectors to operate. The ECM/PCM will allow the fuel injectors to operate until it decides there is no valid password coming from the BCM. If the ECM/PCM does not receive a serial data message, receives a message with an incorrect or unknown password, or receives the fuel disable message from the BCM, engine starting will be disabled.