Operation CHARM: Car repair manuals for everyone.

Idle Speed


Because the idle speed is controlled automatically by the engine control unit through the idle speed control (ISC) solenoid valve, usually it is not necessary to check and adjust the idle speed.
However, when the test connector (Green: 1-pin) is grounded it disables the ECU control of the idle speed. If rough idling due to low idle speed occurs when the test connector is grounded, the idle speed should be adjusted.


1. Check the condition of the engine (spark plugs, leaks in hoses, etc.).
2. Turn all electrical loads OFF.
3. Warm up the engine and run it for three minutes at 2,500-3,000 rpm
in neutral or park.

Fig. 27 Test Connector:





4. Connect a tachometer to engine.
5. Ground the test connector (green: 1-pin) with a jumper wire.
6. Check that the idle speed is within specification.

Idle speed: 650 ± 20 rpm in neutral or park

Fig. 29 Throttle Body Blind Cap:




Fig. 28 Idle Adjustment:





7. If the idle speed is not within specification, remove the blind cap from the air adjusting screw and adjust it by turning the screw.
8. After adjusting the idle speed, disconnect the jumper wire from the test connector.