Serial Data

ECM is equipped with a serial data line. Serial data is a stream of electrical impulses which can be interpreted by special testers of other control modules. On some models, serial data must be accessed using special "Scan" testers connected to the Assembly Line Data Link (ALDL). Update intervals and information contained within the data stream vary with model application.

On models using an ECM and Body Control Module (BCM), serial data may be accessed using the Driver Information Center (DIC) and Climate Control Panel (CCP). On these models, serial data may be shared with BCM, A/C controller, supplemental restraint controller, anti-lock brake controller and even cruise control unit.