Idle Air Control (IAC) Motor

CAUTION: DO NOT apply more than 6 volts to IAC motor.

NOTE: For diagnosis and testing information concerning IAC motor position sensor, see TESTS W/CODES - 2.0L NON-TURBO article.

NOTE: Procedures are provided by manufacturer for component testing using an engine analyzer with oscilloscope capability. Refer to manufacturer's operation manual for instructions in use of oscillo-scope. Go to step 8) for test procedures using oscilloscope.

Using a stethoscope, listen for operation of IAC motor when ignition switch is placed in ON position. If operation cannot be heard, proceed with following tests.
Disconnect IAC motor connector. Using DVOM, measure resistance between IAC motor connector terminal No. 1 and 4 and between terminal No. 2 and 3. Resistance should be 38-52 ohms. Replace motor if resistance is not within specification.
This step checks for continuity between PCM and IAC motor. Disconnect PCM harness connector. Check continuity of specified circuits. See Figure and Fig 1 . See IAC TO PCM CIRCUIT CONTINUITY CHECK table. Check and repair any circuits without continuity.

If preceding tests do not show any system or component malfunction and PCM is suspected, replace PCM and retest system.

IAC TO PCM CIRCUIT CONTINUITY CHECK

Application IAC Terminal No.	PCM Terminal No.
1	34
2	35
3	54
4	55

Fig 1: Identifying IAC Motor Connectors (Eclipse Non-Turbo)

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA

Fig 2: Identifying Good IAC Motor Waveform (Eclipse Non-Turbo)

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA