Idle Air Control (IAC) Valve
See TESTS W/CODES - MOTRONIC 5.2 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 appropriate TESTS W/CODES - MOTRONIC 5.2 SYSTEM or TESTS W/CODES - TRIONIC SYSTEM article.