Component Location
General Description
The Idle Speed Control Actuator (ISCA) is installed on the intake manifold and controls the intake airflow that is bypassed around the throttle plate to keep constant engine speed when the throttle valve is closed. The function of the ISCA is to maintain idle speed according to various engine loads and conditions, and also to provide additional air during starting.
The ISCA consists of an opening coil, a closing coil, and a permanent magnet. Based on information from various sensors, the ECM controls both coils by grounding their control circuits. According to the control signals from the ECM, the valve rotor rotates to control the by pass airflow into the engine.
DTC Description
The ECM monitors engine speed deviation from the target idle engine speed when the vehicle is stopped and the idle speed valve opening is stable.
The ECM sets DTC P0507 if the difference to the target idle engine speed is higher than the predetermined threshold.
If same error code is set in the next driving cycle, the ECM illuminates the MIL.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Signalcheck, High
| Contact resistance in connections
Air leak in intake system
Faulty ISCA
Faulty ECM
|
General Enable Conditions | Vehicle speed = 0
Engine coolant temperature > 70?
Intake air temperature > 20.3?
Altitude < 3000rpm
IdleON
No error in vehicle speed sensor, engine coolant temperature sensor, intake air temperature sensor, purge valve drive stage, purge system, ISA drive stage
|
Case1 | Enable Conditions | Idle speed control torque = -15%
Idle speed controller control duty = 15%
|
Threshold Value | Desired engine speed ? Engine speed < -200rpm
|
Case2 | Threshold Value | Fuel cut-off = 3times
|
Diagnostic Time | 15 sec
|
MIL ON Condition | NO
|
Specification
Temperature | ISCA COIL Resistance |
20 ? | CLOSE COIL | 16.6 ~ 18.6 ? |
OPEN COIL | 14.5 ~ 16.5 ? |
Schematic Diagram
Signal Waveform
The above waveforms are the voltage signals generated when ISCA operates. This ISCA type is duty type and thetime ratio opened determines duty amount. The left side is the waveform of ISCA Openingcoil during idle. The right side is the waveform of ISCA Closing coil during idle.