CELICA, COROLLA, ECHO, MATRIX, RAV4 & TACOMA
Idle speed is controlled by Engine Control Module (ECM) and is not adjustable. Check idle speed with engine at normal operating temperature, transmission/transaxle in Neutral, parking brake applied, air cleaner and all air intake hoses installed, all vacuum hoses installed, electronic fuel injection system wiring connectors properly installed, ignition timing properly set, electric cooling fan off (if equipped), and A/C and all accessories off.
Start engine and warm engine to normal operating temperature. Shut engine off. Connect Toyota hand-held tester or scan tool to data link connector No. 3 at driver's side of instrument panel. See Fig. 75, Fig. 76, Fig. 86 and Fig. 87. Hand-held tester or scan tool is used to read engine RPM.
Apply parking brake. Place transmission/transaxle in Neutral. Start engine and maintain engine at 2500 RPM for 90 seconds and then allow engine to idle while noting idle speed. Ensure idle speed is within specification. See IDLE SPEED SPECIFICATIONS table. Shut engine off. Remove hand-held tester or scan tool.
If idle speed is not within specification, check Idle Air Control (IAC) valve, wiring and Engine Control Module (ECM), and air intake system. See IDLE CONTROL SYSTEMS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.
NOTE:Idle Air Control (IAC) valve is also referred to as Idle Speed Control (ISC) valve.
For Idle Air Control (IAC) system testing procedures, see Fig. 438.
Fig. 438: Inspecting Idle Speed Control Valve (Corolla & Matrix)
Images (Click to enlarge)
Wednesday, December 8th, 2010 AT 5:10 AM