Attention! The engine idle speed is set by the manufacturer and should not be adjusted under normal operating conditions. However, if the throttle chamber has been replaced or it is suspected that the idle speed adjustment has been violated (for example, the idle screw was turned out of the throttle chamber), then the car should be handed over to a car service.
Examination
1. When the ignition is turned off, the idle speed control valve (ISC valve) should make a click.
2. Disconnect the ISC valve connector.
3. Use a jumper to apply voltage to terminals B1 and B2. Connect terminals S1 and S2 to ground, then S3 and S4. The valve plug must extend, i.e. the valve should close.
4. Use a jumper to apply voltage to terminals B1 and B2. Connect terminals S3 and S4 to ground, then S1 and S2. The valve plug must retract, i.e. the valve should open.
5. If the valve does not work, replace it.
6. Check the resistance between terminals B1 and S1, B1 and S3, then between terminals B2 and S2, B2 and S4. Compare the results with those indicated in the technical data (see subsection 5.2.1).
7. If the resistance is normal, then the valve is working (in this case, you should look for a fault in the wiring from the ECM).
8. If the resistance is out of specification, replace the valve.
9. Connect the connector.
Replacement
1. If the screws are difficult to access, remove the damper body.
2. Loosen the fixing screws (indicated by arrows) ISC valve (or IAC valve) to the damper body and remove the valve.
3. When replacing the valve, install the TVV thermal vacuum valve removed from the ISC valve being replaced and replace the gasket.
4. Installation is carried out in the reverse order.