Intervencion Educativa

OPERATION

The Idle Air Control (IAC) valve is used to control idle speed. The amount of air allowed to bypass the throttle plate is determined by the PCM.
When the engine is cold, air flowsthrough the valve during all modes of engine operation to maintain the factory set idle speed.
TESTING

1.8L Engines
See Figure 1

Fig. Fig. 1: Typical IAC valve wiring schematic and connectorterminal identification-1.8L engines
1. Turn the ignition key OFF .
 
2. Connect jumper wires from the sensor connector to the wiring harness. This permits the engine to operate normally whileyou check the sensor.
 
3. Connect a Digital Volt Ohmmeter (DVOM), set to read resistance, between sensor terminal SIG and the negative battery cable.
 
4. The resistance should not begreater than 10,000 ohms.
 
5. Connect the DVOM, set to read resistance, between sensor terminal VPWR and the negative battery cable.
 
6. The resistance should not be greater than 10,000 ohms. 
7. Turn the ignition key ON .
 
8. Connect the DVOM, set to read voltage, between sensor terminal VPWR and the negative battery cable.
 
9. The voltage should be more than 1 volt. 
10. Connect the DVOM, set to read voltage, between sensor terminal SIG and the negative battery cable.
 
11. The voltage should be more than 1 volt.
 
12. If the readings are notwithin specifications, replace the IAC valve.
 

1.9L and 2.0L Engines
See Figures 2, 3 and 4

Fig. Fig. 2: IAC valve (solenoid) connector terminal locations-1.9L and 2.0L engines
1. Turnthe ignition key OFF .
 
2. Unplug the sensor electrical connection.
 

Due to the diode in the IAC valve, be sure to observe the correct polarity when connecting the DVOM.
3. Connect aDigital Volt Ohmmeter (DVOM), set to read resistance, between the sensor terminals as follows. Connect the positive lead to the VPWR terminal and the negative lead to the IAC terminal.
 
4....