System Description

DESCRIPTION
The intake air volume at idle is controlled by opening or closing the motor valve provided in the air path that bypasses the throttle valve.

TROUBLESHOOTING HINTS
1. If the stepper motor step increases to 100 to 120 steps or decreases to 0 step, check for faulty stepper motor or open circuit in the harness.
2. If the idle speed control motor is normal but the stepper motor steps are out of specification, check the following items;
- Poorly adjusted reference idle speed
- Deposit on the throttle valve
- Air leaking into the intake manifold through gasket gap
- Loose exhaust gas recirculation valve seat
- Poor combustion in the cylinder (faulty ignition plug, ignition coil, injector, low compression pressure, etc.)