Modules, Relays & Solenoids: Modules: ECM
WARNING: This page is about a different car, the 1996 Saab 900. However, it is still accessible from the selected car via links, so may be relevant.
See TESTS W/CODES - MOTRONIC 4.1L & 5.2L SYSTEM or BASIC TESTING article. Since many computer controlled and monitored components set a Diagnostic Trouble Code (DTC) if they malfunction, also perform procedures in articles; TESTS W/CODES - MOTRONIC 4.1L & 5.2L SYSTEM or TESTS W/CODES - TRIONIC SYSTEM .