Modules, Relays & Solenoids: Modules: ECM

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 .