The ISCA (Idle Speed Control Actuator) is designed to maintain a steady desired idle speed. Idle airflow is adjusted through the idle air actuator in order to maintain the desired idle speed under various load conditions. Load conditions vary due to numerous factors, such as engine temperature, air conditioning, electrical load and power steering load.
If actual engine speed is more than 200 RPM higher than desired engine speed, P0507 is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
Rationality check, high
Poor connection
Leak in intake air system
Carbon pile
ISCA
General
Enable
Conditions
Vehicle speed = 0
Coolant temperature > 80?
Intake air temperature > 15?
Idle status
No error on the related sensors. (PCSV, VSS, ECTS, IATS, etc)
Case 1
Idle speed control torque = -5%
Threshold Value
Desired engine speed – Engine speed < -200rpm
Case 2
Fuel cut-off = 3times
Diagnostic Time
15 sec.
MIL ON Condition
3 driving cycle
Specification
Opening Coil Resistance (O)
11.1 ~ 12.7 [20 ? 68 ?]
Closing Coil Resistance (O)
14.6 ~ 16.2 [20 ? 68 ?]
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.