Idle Air Control (IAC) Valve
NOTE:
IAC valve may also be referred to as Idle Speed Control (ISC) valve.
- Warm engine to normal operating temperature. Ensure idle speed is correct. See ADJUSTMENTS article.
- Apply parking brake and place transmission/transaxle in Neutral. Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 of data link connector No. 1. See Fig 1. Start engine and note engine RPM.NOTE: Data link connector No. 1 is located under below driver's seat.
- Engine RPM should increase to specified engine RPM for 5 seconds and then decrease approximately 200 RPM. See IAC VALVE ENGINE SPEED TESTING SPECIFICATIONS table.
- If engine RPM is not as specified, check IAC valve resistance and operation. If engine RPM is within specification, remove jumper wire. Turn ignition off.
- To check IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve located on lower area of throttle body. Using ohmmeter, measure resistance between terminal B+ and each remaining terminal. See Fig 1.
- Replace IAC valve if resistance is not within specification. See IAC VALVE RESISTANCE SPECIFICATIONS table.
IAC VALVE ENGINE SPEED TESTING SPECIFICATIONS
| Application | Engine RPM |
|---|---|
| Previa | 1000-1200 |
NOTE:
Information is not available from manufacturer for checking IAC valve operation for Previa.
IAC VALVE RESISTANCE SPECIFICATIONS
| Application | Ohms |
|---|---|
| Previa | 18.8-22.8 |
ECM LOCATION
| Model | Location |
|---|---|
| Previa | Under Driver's Seat |