Idle Air Control (IAC) System Check: Troubleshooting

DIAGNOSIS PROCEDURE

Step	Action	YES	NO
1	Do you have SUZUKI scan tool?	Go to Step 2.	Go to Step 3.
2	Engine idle speed and IAC duty check Check idle speed / idle air control duty referring to IDLE SPEED / IDLE AIR CONTROL (IAC) DUTY INSPECTION . Is check result as specified?	Go to Step 3.	Go to Step 5.
3	Idle air control valve check Turn headlight, heater blower and/or rear defogger switch to ON. Is idle speed kept specified speed?	Go to Step 4.	Go to Step 6.
4	Is engine idle speed kept specified speed even with steering wheel turned to the right or left as far as it stops (vehicle with power steering system)?	System is in good condition.	Check power steering pressure switch signal circuit referring to POWER STEERING PRESSURE (PSP) SWITCH SIGNAL CIRCUIT CHECK . If check result is OK, go to Step 6.
5	Air intake system check Check air intake system for clog and air inhaling. Is check result satisfactory?	Go to Step 6.	Repair or replace.
6	Idle air control valve operation check Check idle air control valve for operation referring to IDLE AIR CONTROL (IAC) VALVE OPERATION CHECK . Is check result satisfactory?	Go to Step 8.	Go to Step 7.
7	Idle air control valve check Check idle air control valve for resistance and operation referring to IDLE AIR CONTROL (IAC) VALVE INSPECTION . Is check result as specified?	"BLK/RED", "GRN/RED", "GRN/ORN", "RED/BLU" or "WHT/GRN" circuit open or short. If wire and connections are OK, substitute a known-good ECM and recheck.	Clean or replace idle air control valve.
8	Air conditioning (A/C) signal check Check A/C signal circuits referring to A/C SIGNAL CIRCUITS CHECK (VEHICLE WITH A/C) , if equipped. Is it in good condition?	Go to Step 9.	Repair or replace A/C signal circuits or A/C system.
9	Check parts or system which can effect idle speed / IAC duty Check the accessory engine road Check the EGR valve malfunction (leakage) Check the EVAP system malfunction (leakage) Check the Engine mechanical (Compression) Check the TP sensor performance Check the ECT sensor performance Check the stuck of PCV valve Are they in good condition?	Substitute known-good ECM and recheck.	Repair or replace.