Idle Air Control (IAC) Solenoid
- If IAC solenoid circuit is open or shorted, a Diagnostic Trouble Code (DTC) should set. See appropriate TESTS W/CODES
article. If any DTCs are present, repair as necessary. If no DTCs are present, go to next step.
- To check IAC solenoid, connect New Generation Star (49 T088 0A0) scan tool to Data Link Connector (DLC) 2. DLC is located under left side of instrument panel, right of steering column. Turn ignition on. Using scan tool, access DIAGNOSTIC DATA LINK menu, and select PCM. Highlight and select PID/DATA MONITOR AND RECORD.
- Start engine and operate at idle. Using scan tool, access IAC PID and record value while operating vehicle under specified condition. See IDLE AIR CONTROL (IAC) SOLENOID SPECIFICATIONS
table. If IAC PID value is not as specified, go to next step.
- Turn ignition off. Disconnect IAC solenoid connector. Using ohmmeter, measure resistance between IAC solenoid terminals. A diode is located in solenoid; connect ohmmeter positive test lead to VPWR terminal (Red wire) and negative lead to IAC SIG terminal (White/Light Blue wire). Resistance should be 6-13 ohms at 68°F (20°C). If resistance is not as specified, replace IAC solenoid.
IDLE AIR CONTROL (IAC) SOLENOID SPECIFICATIONS
| Condition |
Volts |
% Duty Cycle |
| Ign On/Eng Off |
VBAT |
0 |
| Hot Idle |
11-11.7 |
28-32 |
| 30-55 MPH |
7.6-10 |
30-55 |
| 55-65 MPH |
9.1-10.4 |
|