{"model":"mk4","model_name":"MK4 Supra","vehicle":"Toyota Supra A80 (1993–2002, 2JZ-GE / 2JZ-GTE)","document":"Repair Manual","section":"TGE","section_name":"Troubleshooting 2JZ-GE","page":95,"pages_in_section":105,"title":"IAC Valve Circuit","section_header":"Engine — 2JZ-GE Engine Troubleshooting","ocr_text":"IAC Valve Circuit\n\nCIRCUIT DESCRIPTION\nThe IAC valve is situated on the intake chamber. Intake\nair bypassing the throttle valve is directed to the IAC\nvalve through a passage.\nA step motor is built into the IAC valve. It consists of 4\ncoils, a magnetic rotor, valve shaft and valve.\nWhen current flows to the coils due to signals from the\nECM, the rotor turns and moves the valve shaft forward\nor backward, changing the clearance between the\nvalve and the valve seat.\nIn this way the intake air volume bypassing the throttle\nvalve is regulated, controlling the engine speed.\nThere are 125 possible positions to which the valve can\nbe opened.\n\nThrottle Body\nAir\nFlow\nMeter\nIntake\nAir\nChamber\nValve\nCoils\nRotor\nValve Shaft\n\nFI6511\n\nReference     INSPECTION USING OSCILLOSCOPE\n\nA/C Switch OFF → ON\n(IAC Valve open)\nISC1\nISC2\n20 V/Div.\nISC3\nISC4\n10 msec./Division\n\n• With the engine idling measure wave forms\nbetween terminals ISC1, ISC2, ISC3, ISC4\nand E01 of engine control module when\nA/C switch ON or OFF.\n\nHINT:\nThe correct waveforms are as shown.\n\nA/C Switch ON → OFF\n(IAC Valve close)\nISC1\nISC2\n20 V/Div.\nISC3\nISC4\n10 msec./Division\n\nFI6538\nFI6537","image":"https://tsrm.sasquatchvc.com/images/mk4/TGE/TGE_095.png","url":"https://tsrm.sasquatchvc.com/mk4/tsrm/TGE/95","prev":{"page":94,"url":"https://tsrm.sasquatchvc.com/mk4/tsrm/TGE/94","api":"https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/94"},"next":{"page":96,"url":"https://tsrm.sasquatchvc.com/mk4/tsrm/TGE/96","api":"https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/96"},"section_url":"https://tsrm.sasquatchvc.com/mk4/tsrm/TGE","section_api_pages":["https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/1","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/2","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/3","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/4","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/5","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/6","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/7","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/8","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/9","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/10","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/11","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/12","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/13","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/14","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/15","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/16","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/17","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/18","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/19","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/20","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/21","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/22","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/23","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/24","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/25","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/26","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/27","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/28","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/29","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/30","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/31","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/32","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/33","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/34","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/35","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/36","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/37","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/38","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/39","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/40","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/41","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/42","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/43","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/44","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/45","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/46","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/47","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/48","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/49","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/50","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/51","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/52","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/53","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/54","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/55","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/56","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/57","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/58","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/59","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/60","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/61","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/62","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/63","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/64","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/65","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/66","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/67","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/68","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/69","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/70","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/71","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/72","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/73","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/74","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/75","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/76","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/77","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/78","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/79","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/80","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/81","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/82","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/83","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/84","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/85","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/86","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/87","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/88","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/89","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/90","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/91","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/92","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/93","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/94","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/95","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/96","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/97","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/98","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/99","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/100","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/101","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/102","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/103","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/104","https://tsrm.sasquatchvc.com/api/pages/mk4/tsrm/TGE/105"],"note":"OCR transcript of a scanned Toyota factory manual page; verify critical values (torque specs, part numbers) against the image."}