The modulator is installed in the air duct that bypasses the throttle valve. By passing additional air, the modulator regulates the idle speed of the engine crankshaft.
Examination
1. Disconnect the connector from the idle speed control modulator.
2. Measure the resistance between the connector terminals. Resistance between terminals 1 and 2: 10.5-14 ohms Resistance between terminals 2 and 3: 10-12.5 ohms at 20°C.
3. Connect the connector to the idle speed control modulator.