Idle Speed Control: 4-Cylinder
- Engine coolant temperature should be 176-203°F (80-95°C). Turn all accessories off. DO NOT check curb idle speed while cooling fan is operating. Place transmission in Neutral or Park. On power steering-equipped vehicles, ensure steering wheel and front wheels are in straight-ahead position.
- Loosen accelerator cable. Connect a tachometer. Connect a digital voltmeter between ground terminal (Black wire) and signal terminal (Light Green wire) of Motor Position Sensor (MPS) connector. Backprobe MPS connector. DO NOT disconnect MPS connector.
- Turn ignition switch to ON position for at least 15 seconds. This sets ISC motor in idle position. Check voltage at MPS, output voltage should be .9 volt. Turn ignition switch to LOCK position. Disconnect ISC servomotor connector. Put ISC motor in retracted position.
- Open throttle valve by hand 2-3 times and allow valve to return with a snap each time. Loosen fixed Speed Adjusting Screw (SAS). See Fig 1 .
- Start engine and run at idle. Check engine speed and MPS output voltage. Engine speed should be 600-800 RPM (650-850 RPM on Sonata 2.4L). If engine speed is not within specification, adjust idle speed with ISC adjusting screw. See Fig 1 .
- Tighten fixed speed adjusting screw until RPM increases. Loosen screw until RPM ceases to drop (touch point), then loosen screw an additional 1/2 turn. Check Throttle Position Sensor (TPS) adjustment. See THROTTLE POSITION SENSOR .
- Turn ignition off and adjust accelerator cable. Connect ISC motor connector. Disconnect harness and voltmeter.
- Start engine and ensure idle speed is 600-800 RPM (650-850 RPM on Sonata 2.4L). Turn ignition off. Disconnect battery for 15 seconds to erase diagnostic memory. Reconnect battery. Readjust accelerator cable. See ACCELERATOR CABLE PLAY SPECIFICATION table.
ACCELERATOR CABLE PLAY SPECIFICATION
| Application | In. (mm) |
|---|---|
| Auto. Trans. | .08-.12 (2-3) |
| Man. Trans. | 0-.04 (0-1) |