The ISCA (Idle Speed Control Actuator) is designed to maintain a steady desired idle speed. Idle airflow is adjustedthrough 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
Circuit continuity check, low
Poor connection
Open or short to ground in control circuit
ISCA
Enable Conditions
IG ON
Battery voltage 10~16V
Engine speed = 500 rpm
70? ? Coolant temperture < 150?
Intake air temperature : -10~80 ?
atmospheric pressure > 75 kPa
ISC F/B update inhibition condition is not satisfied
ISC F/B execution condition satisfaction
Threshold Value
Engine speed - Desired engine speed > 200 rpm
Diagnostic Time
3 times, 15000 msec
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.